Autosomal dominant intellectual developmental disorder 23 is a rare genetic condition that affects learning and development. People with Autosomal dominant intellectual developmental disorder 23 often have mild to moderate intellectual disability and may have delayed speech and motor skills. Signs usually appear in early childhood and tend to be lifelong, but abilities can improve with support. Treatment focuses on therapies like speech, occupational, and educational support, and doctors may address associated features if present. Not everyone will have the same experience, and most people live into adulthood with appropriate care.
Overview
Autosomal dominant intellectual developmental disorder 23Symptoms
Autosomal dominant intellectual developmental disorder 23 is typically recognized in early childhood with global developmental delay and learning difficulties. Common features include speech and language delay, motor milestones lagging, and variable behavioral differences. Some children also show subtle facial features.
Outlook and prognosis
Many living with autosomal dominant intellectual developmental disorder 23 make steady gains with early therapies, tailored education, and family support. Outlook varies widely, from mild learning challenges to broader developmental needs. Regular check-ins with neurology, cardiology, and behavioral teams help guide progress over time.
Causes and risk factors
Autosomal dominant intellectual developmental disorder 23 results from a single-gene change passed in an autosomal-dominant pattern, often arising as a new (de novo) mutation. Main risk factor is an affected parent; advanced parental age slightly increases de novo mutation likelihood.
Genetic influences
Genetics are central in Autosomal dominant intellectual developmental disorder 23. Single-gene variants, inherited or new (de novo), typically cause it; each child of an affected parent has a 50% chance. Genetic testing confirms the diagnosis and guides family planning.
Diagnosis
Doctors suspect Autosomal dominant intellectual developmental disorder 23 from developmental history, learning and other features, then confirm with genetic testing identifying a gene change. Early genetic diagnosis of Autosomal dominant intellectual developmental disorder 23 can guide care and family planning.
Treatment and drugs
Treatment for Autosomal dominant intellectual developmental disorder 23 focuses on building skills and easing day-to-day challenges. Care often includes early developmental therapies, individualized education plans, speech and occupational therapy, behavior supports, and monitoring for seizures or sleep issues. Genetic counseling and coordinated care help families plan ahead.
Symptoms
Daily life with this genetic condition can mean developmental milestones arrive later and learning takes extra time. Early features of Autosomal dominant intellectual developmental disorder 23 often appear in infancy or early childhood, especially around speech, movement, and learning. Features vary from person to person and can change over time. Doctors look for a pattern across growth, behavior, and development rather than any single sign.
Milestones like sitting, walking, or using words may happen later than expected. This can make daily routines like dressing or feeding take more practice.
Learning new ideas and school skills may take extra time and support. In Autosomal dominant intellectual developmental disorder 23, many benefit from individualized education plans and repetition.
First words, combining words, or clear speech can be delayed. In Autosomal dominant intellectual developmental disorder 23, speech and language are commonly affected, and therapy can make a meaningful difference.
Fine motor tasks like buttoning, writing, or using utensils can be harder. Balance and coordination may improve with occupational and physical therapy.
How people usually first notice Autosomal dominant intellectual developmental disorder 23?
Many families first notice signs in early childhood when speech is delayed, learning new skills takes longer than expected, or a child needs more support with attention and problem-solving. Doctors may pick up the pattern during routine checkups or early school evaluations, noting global developmental delay, mild differences in facial features, or growth and motor coordination that lag peers. For many, these early clues prompt genetic testing, which confirms the diagnosis and helps guide early therapies—this is often how the first signs of Autosomal dominant intellectual developmental disorder 23 are recognized.
Types of Autosomal dominant intellectual developmental disorder 23
People with Autosomal dominant intellectual developmental disorder 23 can share core features, but the exact mix and intensity can vary from one person to another. Researchers describe these categories to better understand patterns of the condition. When people look up types of Autosomal dominant intellectual developmental disorder 23, they’re usually asking how symptom patterns differ rather than separate genetic subtypes. Not everyone will experience every type.
Cognitive learning
Challenges with problem-solving and learning new skills are common. Many need extra time for school tasks and daily planning. Supports like tailored teaching and therapy often help progress over time.
Language and speech
Speech may be delayed, and expressive language can lag behind understanding. Some may use short phrases or need help finding words. Speech therapy can improve clarity and communication.
Behavior and attention
Inattention, hyperactivity, or impulsivity can be more noticeable than in peers. Some may also have anxiety, mood shifts, or repetitive behaviors. Care plans often combine behavioral strategies with school supports.
Motor coordination
Fine and gross motor skills may develop later than expected. Tasks like buttoning clothes, handwriting, or sports can be harder. Physical and occupational therapy can build coordination and confidence.
Growth and feeding
In infancy, slow weight gain or feeding difficulties can appear. Gastrointestinal discomfort or picky eating may continue in some children. Nutrition guidance can help maintain steady growth.
Sleep differences
Falling asleep or staying asleep can be difficult. Daytime tiredness may affect learning and behavior. Consistent routines and sleep hygiene strategies often make a difference.
Sensory processing
Some are sensitive to sound, textures, or light, while others seek extra movement or pressure. These differences can affect clothing choices, classroom comfort, and focus. Occupational therapy can tailor sensory supports.
Seizure risk
A minority experience seizures, often starting in childhood. Seizures can range from brief staring spells to convulsive events. Neurology care and medication typically manage episodes well.
Physical features
Mild facial or body differences may be present but often subtle. Doctors may note features on examination that do not affect health directly. These can help confirm the diagnosis alongside genetic testing.
What genetics can tell you about symptoms
Some people with autosomal dominant intellectual developmental disorder 23 have variants in the GRIN2B gene that disrupt NMDA receptors, leading to learning delays, speech difficulties, and sometimes seizures. Certain variants also relate to autism-like features, attention challenges, low muscle tone, and motor coordination delays.
Causes and risk factors
Autosomal dominant intellectual developmental disorder 23 is caused by a single gene change that affects brain development. The change can be inherited from a parent, and it often happens for the first time in a child. Genes set the stage, but environment and lifestyle often decide how the story unfolds. Family history is the main risk factor, and a parent with the change has a 50% chance of passing it on with each pregnancy. Other risk factors for Autosomal dominant intellectual developmental disorder 23 are limited, and early supports and overall health can shape severity and outcomes.
Environmental and biological risk factors
Most cases of Autosomal dominant intellectual developmental disorder 23 happen because of a new change that arises around conception, not because of anything a parent did or didn’t do. Doctors often group risks into internal (biological) and external (environmental). A few factors can slightly raise the chance that this kind of new change will occur, while everyday exposures typically do not. Below are the environmental and biological elements linked to a higher likelihood.
As sperm-producing cells divide over many years, small DNA changes become more likely. Older paternal age can slightly raise the risk of Autosomal dominant intellectual developmental disorder 23.
Eggs also age over time, and rare new DNA changes can arise. This effect is smaller than the paternal-age effect but may modestly increase risk.
Significant exposure to ionizing radiation before conception can damage DNA in sperm or eggs. Routine medical X-rays and airport scanners use very low doses and are not expected to meaningfully increase risk.
Some chemotherapy medicines and pelvic or total-body radiation can temporarily increase DNA damage in reproductive cells. Timing conception with your oncology team’s guidance can reduce the small risk of a treatment-related new change.
Genetic risk factors
Autosomal dominant intellectual developmental disorder 23 stems from a harmful change in a single gene and follows an autosomal dominant pattern. Many cases happen for the first time in a child (a de novo change), while an affected parent can also pass it on. Risk is not destiny—it varies widely between individuals. Genetic testing can clarify the genetic causes of Autosomal dominant intellectual developmental disorder 23 and whether it runs in a family.
Single-gene variant: A change in one copy of the responsible gene disrupts brain development and learning. The change can be small (a single-letter swap) or larger, and it alters how the gene works.
Dominant inheritance: If a parent carries the gene change, each child has a 50% chance to inherit it. All sexes can be affected equally.
De novo change: In many families, the change is new in the child and not present in either parent. When this is confirmed, the chance of it happening again in a future pregnancy is generally low.
Parental mosaicism: Sometimes a parent has the change in a small portion of egg or sperm cells, so standard blood testing looks negative. This creates a small, above-average chance of recurrence in future pregnancies.
Copy-number change: A small missing or extra piece of DNA that includes the gene can cause the same condition. The size and position of the piece can influence which features are seen.
Translocation disruption: A chromosome swap (a translocation) that breaks the gene can lead to the disorder, even if the swap looks balanced. Specialized genetic testing may be needed to detect this.
Variable expression: The same gene change can lead to different learning or developmental needs from person to person, even within one family. Severity in one relative does not predict how someone else may be affected.
Family history clues: Learning differences or developmental delays in multiple relatives can point to an inherited change. Testing family members can show who carries the change and refine true recurrence risks.
Variant classification: Only variants labeled pathogenic or likely pathogenic confirm this diagnosis. A “variant of uncertain significance” should not guide risk or care until more evidence is available.
Lifestyle risk factors
Autosomal dominant intellectual developmental disorder 23 is a genetic condition; lifestyle habits do not cause it, but they can shape daily function, symptoms, and complications. Thoughtful routines, nutrition, sleep, activity, and communication supports can meaningfully improve comfort and skills. Understanding how lifestyle affects Autosomal dominant intellectual developmental disorder 23 helps families prioritize changes with the biggest impact.
Poor or irregular sleep can worsen irritability, attention, learning, and lower seizure threshold if seizures are present. A consistent schedule and calming wind-down can stabilize daytime behavior and function.
Inadequate calories or micronutrients can amplify low energy, growth concerns, and constipation common in neurodevelopmental conditions. Texture-appropriate, fiber-rich meals with good hydration can support growth, bowel regularity, and feeding comfort.
Rapid eating or unsafe textures raise choking and aspiration risk in those with oral–motor challenges. Slow pacing, upright positioning, and safe textures make meals safer and less stressful.
Regular, tailored movement can improve muscle tone, coordination, endurance, and participation in therapy. Activity also reduces constipation and may improve sleep quality.
Risk prevention
For most, Autosomal dominant intellectual developmental disorder 23 is genetic and not something you can fully prevent. Prevention is about lowering risk, not eliminating it completely. What you can do is lower the chance of complications, spot needs early, and build steady supports at home and school. Because early symptoms of Autosomal dominant intellectual developmental disorder 23 can be subtle, regular developmental check-ins can make a real difference.
A genetics professional can explain inheritance and your family’s specific risks. In autosomal dominant conditions, each pregnancy may have about a 50% chance of inheriting the variant.
If you want to reduce the chance of passing on the condition, options may include IVF with embryo testing or prenatal testing. A counselor can review benefits, limits, and timing for each choice.
Regular developmental screening can flag early symptoms of Autosomal dominant intellectual developmental disorder 23, such as delays in speech or motor skills. Early intervention services can support learning, communication, and movement from infancy onward.
Consistent visits with your pediatrician and specialists help track growth, hearing, vision, sleep, and feeding. Finding and treating issues early can prevent avoidable complications and hospital visits.
Transmission
Autosomal dominant intellectual developmental disorder 23 is not infectious—you cannot catch it from someone or spread it to others. It is inherited in an autosomal dominant pattern, meaning a change in one copy of a gene is enough to cause the condition; if a parent has it, each pregnancy has a 50% chance (1 in 2) of passing it on. In many families, the gene change happens for the first time in the child (a new genetic change), so neither parent has the condition. Genetic testing and counseling can help families understand how Autosomal dominant intellectual developmental disorder 23 is inherited and the chance of it happening again.
When to test your genes
Consider genetic testing if you or a close relative have lifelong learning differences, speech delays, or attention/behavior challenges suggestive of Autosomal dominant intellectual developmental disorder 23, especially with a similar family history. Testing is also reasonable before family planning or when results could tailor therapies, school supports, or medical monitoring. Start by discussing a referral to a genetic counselor or clinical geneticist.
Diagnosis
Small signs in everyday life often spark the evaluation—late first words, trouble learning new skills, or needing extra support at school. Genetic testing may be offered to clarify risk or guide treatment. When doctors suspect this condition, they look for patterns in development and features and then confirm with lab-based genetic tests; this is the genetic diagnosis of Autosomal dominant intellectual developmental disorder 23. Some diagnoses are clear after a single visit, while others take more time.
Providers review early milestones like sitting, walking, and first words. They look for delays across speech, learning, and motor skills. Consistent patterns help focus testing.
A head-to-toe exam checks growth, muscle tone, joints, and facial features. Subtle combinations of findings can point toward a genetic cause. Photos or measurements may be recorded for accuracy.
Doctors assess reflexes, coordination, and muscle strength. They also ask about seizures, unusual movements, or sleep concerns. This helps separate brain-based causes from other issues.
Age-appropriate tools measure learning, problem-solving, and language. Results clarify the level of support needed at school and home. They also guide which medical tests are most useful.
Stages of Autosomal dominant intellectual developmental disorder 23
Autosomal dominant intellectual developmental disorder 23 does not have defined progression stages. It is a lifelong neurodevelopmental condition, so abilities usually develop at an individual pace and can improve with therapies rather than showing a steady decline. In practice, early symptoms of Autosomal dominant intellectual developmental disorder 23 may include delays in speech, learning differences, or later motor milestones, and clinicians look at these patterns alongside exams and developmental testing. Genetic testing may be offered to clarify certain risks, confirm the diagnosis, and guide supports.
Outlook and prognosis
Daily routines often adapt for people with Autosomal dominant intellectual developmental disorder 23 (ADIDDI23), with extra time for learning, structured supports at school, and therapies to build communication and daily living skills. The outlook is not the same for everyone, but many living with ADIDDI23 make steady gains when speech, occupational, and behavioral therapies start early and are kept consistent. Doctors call this the prognosis—a medical word for likely outcomes. Most children continue to learn through adolescence and adulthood, though they may need ongoing educational support and help with planning, safety, and social skills.
Some people experience mild intellectual disability with limited medical issues, while others notice more significant developmental delays, behavioral challenges, or seizures. Early symptoms of Autosomal dominant intellectual developmental disorder 23 can include delayed first words, trouble with fine motor tasks like using utensils, and learning differences that become clearer in school years. Life expectancy is generally close to typical when major medical complications are absent; serious health risks usually relate to coexisting conditions such as poorly controlled epilepsy, feeding difficulties, or sleep-disordered breathing, which care teams can often manage. With ongoing care, many people maintain good overall health and participate in family, school, and community life.
Looking at the long-term picture can be helpful. In medical terms, the long-term outlook is often shaped by both genetics and lifestyle. Genetic testing can sometimes provide more insight into prognosis. Talk with your doctor about what your personal outlook might look like.
Long-term effects
Autosomal dominant intellectual developmental disorder 23 is a lifelong genetic condition, so its features tend to be stable or evolve gradually across childhood, adolescence, and adulthood. Long-term effects vary widely, so strengths and challenges can look different from one person to the next. Many living with Autosomal dominant intellectual developmental disorder 23 continue to learn skills over time, but may need ongoing supports. Early features often show up in infancy or early childhood and may shape school and adult independence later on.
Most people have mild to moderate intellectual disability that persists into adulthood. Learning new concepts can take longer, but progress often continues across the years.
First words and phrases may come later than peers. Ongoing expressive language challenges are common, while understanding is often stronger than speaking.
Reading, writing, and math skills usually improve slowly with repetition. School performance often shows uneven strengths, such as better visual learning than abstract reasoning.
Inattention, hyperactivity, or impulsivity can be part of the long-term picture. Some may also have anxiety or mood challenges that fluctuate over time.
How is it to live with Autosomal dominant intellectual developmental disorder 23?
Living with autosomal dominant intellectual developmental disorder 23 often means learning and working at a different pace, with supports that make thinking, communication, and daily routines easier to manage. Many people benefit from structured schedules, clear visual cues, speech and occupational therapies, and extra time for tasks at school, work, and home. Families, caregivers, and classmates may notice that patience, consistent guidance, and celebrating small steps forward make a big difference, and siblings or peers often become natural advocates and coaches. With the right accommodations and a team approach, many find stable routines, meaningful learning, and strong relationships that support independence over time.
Treatment and drugs
Treatment for Autosomal dominant intellectual developmental disorder 23 focuses on building skills and easing day-to-day challenges rather than “curing” the condition. Supportive care can make a real difference in how you feel day to day. Plans often include early intervention, special education, speech and language therapy, occupational and physical therapy, and behavioral strategies; many people also benefit from psychological support for anxiety, attention, or mood symptoms, sometimes with medicines such as stimulants or SSRIs when clinically appropriate. Doctors sometimes recommend a combination of lifestyle changes and drugs. Regular follow-up with a developmental pediatrician, neurologist, or clinical geneticist helps tailor supports over time, and care coordination can include school-based services, transition planning for adulthood, and family counseling.
Non-drug treatment
Living with Autosomal dominant intellectual developmental disorder 23 can affect learning, communication, movement, and day-to-day independence in different ways from childhood onward. Non-drug treatments often lay the foundation for progress and independence. Spotting early symptoms of Autosomal dominant intellectual developmental disorder 23 and starting supports early can help build skills over time. Needs vary, so plans are tailored and may change as children grow into adulthood.
Team-based services in infancy and preschool can boost language, motor, and social skills. Starting early helps the brain build new pathways. This is often the first step after diagnosis of Autosomal dominant intellectual developmental disorder 23.
Work on understanding and using words, clear speech, and social communication. Therapy may also target feeding and oral-motor skills when needed.
Build fine-motor skills, hand strength, and daily living routines like dressing or using utensils. Therapists adapt tasks and tools to make activities achievable and safe.
Improve posture, balance, coordination, and walking. Targeted exercises can help with low or high muscle tone and prevent tightness.
Your genes may have an impact on how drugs work for you
Medicines for autosomal dominant intellectual developmental disorder 23 can work differently depending on a person’s genetic variants, which may change how drugs are processed or how brain receptors respond. Pharmacogenetic testing can sometimes guide dosing or drug choice, helping improve benefits and limit side effects.
Pharmacological treatments
Medicines for Autosomal dominant intellectual developmental disorder 23 focus on easing day-to-day symptoms like attention challenges, seizures, sleep issues, anxiety, and irritability. There isn’t a drug that changes the underlying genetic cause, so treatment is tailored to what affects you or your child most. Not everyone responds to the same medication in the same way. Doctors often start with well-studied options and adjust based on benefits and side effects.
Methylphenidate or amphetamine stimulants can improve focus and reduce hyperactivity. Atomoxetine, guanfacine, or clonidine are non-stimulant options if stimulants aren’t a good fit.
Levetiracetam, valproate, or lamotrigine are common anti-seizure choices. Your care team may add rescue medicines like diazepam nasal spray or buccal midazolam for prolonged seizures.
Risperidone or aripiprazole may reduce severe irritability that disrupts learning or care. Doctors watch for weight gain or movement-related side effects and adjust as needed.
SSRIs such as sertraline, fluoxetine, or escitalopram can ease anxiety or low mood in people with Autosomal dominant intellectual developmental disorder 23. Dosing may be increased or lowered gradually to balance benefits and side effects.
Genetic influences
It follows an autosomal dominant pattern, meaning a change in just one copy of the gene can lead to the features seen with this condition. Family history is one of the strongest clues to a genetic influence. If a parent has this gene change, each child has about a 50% chance of inheriting it.
That said, many people with Autosomal dominant intellectual developmental disorder 23 are the first in their family to be diagnosed because the gene change can arise for the first time in the egg or sperm. How it shows up can differ from person to person, even in the same family; one sibling might have milder learning challenges while another needs more day-to-day support. Genetic testing for Autosomal dominant intellectual developmental disorder 23 can often find the underlying gene change, and meeting with a genetic counselor can help you understand results, plan next steps, and discuss future pregnancy options, including the small possibility of a parent carrying the change in only some cells (mosaicism).
Is Autosomal dominant intellectual developmental disorder 23 genetic?
Genetics are central in Autosomal dominant intellectual developmental disorder 23. Single-gene variants, inherited or new (de novo), typically cause it; each child of an affected parent has a 50% chance. Genetic testing confirms the diagnosis and guides family planning.
Pharmacogenetics—how genetics influence drug effects
For Autosomal dominant intellectual developmental disorder 23, medications are usually chosen to address day-to-day needs like seizures, attention or mood symptoms, sleep issues, and challenging behaviors. The gene change that causes Autosomal dominant intellectual developmental disorder 23 doesn’t usually determine which drug will work best, but other genes that control how the body handles medicines can influence dosing, side effects, and benefit. A “slow metabolizer” may process medicine more slowly, leading to stronger effects or side effects at typical doses. Examples include checking for a specific HLA type (HLA-B*15:02) in many people of Asian ancestry before starting carbamazepine or oxcarbazepine, using genetic results to adjust doses of atomoxetine, risperidone or aripiprazole, and tailoring certain antidepressants (like citalopram or sertraline) or seizure medicines such as phenytoin. Pharmacogenetic panel testing, considered alongside age, weight, other prescriptions, and medical history, can help personalize medications used to treat Autosomal dominant intellectual developmental disorder 23 and lower the chance of adverse effects. This testing doesn’t replace close follow-up, but it can cut down on trial and error when past treatments caused side effects or didn’t help.
Interactions with other conditions
Day to day, people with Autosomal dominant intellectual developmental disorder 23 may also deal with issues like congenital heart differences, seizures, autism-like traits, sleep apnea, feeding challenges, or reflux, and these can add up to affect learning, behavior, and energy. Doctors call it a “comorbidity” when two conditions occur together. If a heart defect is present, it can influence growth, stamina, and anesthesia risk; some behavior or attention medicines may need a cardiology check before starting. When epilepsy occurs, it can make attention and language harder, and poor sleep or fevers may trigger seizures, so treating sleep apnea and promptly managing infections can help stabilize things. Low muscle tone can contribute to scoliosis and constipation, and supportive therapies and bowel routines often improve comfort and mobility. Hearing or vision problems can mimic or magnify early symptoms of Autosomal dominant intellectual developmental disorder 23, so regular screening and timely correction can make a real difference in progress.
How genes can cause diseases
Humans have more than 20,000 genes, each carrying out one or a few specific functions in the body. One gene instructs the body to digest lactose from milk, another tells the body how to build strong bones and another prevents the body's cells from beginning to multiply uncontrollably and developing into cancer. As all of these genes combined are the building instructions for our body, a defect in one of these genes can have severe health consequences.
Through decades of genetic research, we know the genetic code of any healthy/functional human gene. We have also identified that in certain positions on a gene, some individuals may have a different genetic letter from the one you have. We call these hotspots "Genetic Variations" or "Variants" in short. In many cases, studies have been able to show that having the genetic letter "G" in the position makes you healthy, but having the letter "A" in the same position disrupts the gene function and causes a disease. Genopedia allows you to view these variants in genes and summarizes all that we know from scientific research, which genetic letters (Genotype) have good or bad consequences on your health or on your traits.
History
Throughout history, people have described children who learned more slowly than their peers, spoke later, or needed extra help in school, while other abilities—like social warmth or curiosity—stood out. Families sometimes noticed a pattern across generations: a parent and child with similar learning needs, or several relatives who shared slower speech and mild differences in attention or behavior. These everyday observations echo what modern clinicians now group under Autosomal dominant intellectual developmental disorder 23.
First described in the medical literature as a cluster of learning and developmental differences within the same family, the condition was initially understood mainly through careful interviews and developmental testing. Early reports focused on what teachers and parents noticed—later milestones, support needs in reading and math, or challenges with planning and focus. As more families were documented, doctors recognized that the features could be quite variable, even within a single family. Some people had mild learning differences and lived independently with minimal support, while others needed more structured help through school and adulthood.
In recent decades, knowledge has built on a long tradition of observation. What began as family stories and clinical checklists moved into the era of genetic testing. Researchers identified a repeatable pattern: the condition tends to appear when a single altered gene is passed from a parent or arises as a new change in the child, which is why it’s described as “autosomal dominant.” This shift—from describing outward signs to pinpointing a genetic cause—allowed clearer diagnosis, more consistent naming, and better counseling for families planning future pregnancies.
Over time, descriptions became more precise. Specialists learned that Autosomal dominant intellectual developmental disorder 23 spans a wide range of learning and adaptive skills. Some children show early speech and language delays; others mainly struggle with attention or processing speed. Doctors also noted small, nonspecific physical features in some people—details that supported the diagnosis but were not required for it. This broader picture helped avoid narrow labels and reduced the risk of missing milder cases.
Looking back helps explain why the condition was once considered rare. Without genetic tools, many people with mild features were never linked under the same diagnosis. With modern testing, families finally had a name that fit their experience, and clinicians could separate this condition from other, similar developmental disorders. Awareness of past misunderstandings can also guide care today: early evaluation, educational supports, and attention to mental health often make a meaningful difference in daily life.
Today’s understanding reflects this journey—from family observations to genetic clarity—while recognizing that each person’s profile is unique. The history of Autosomal dominant intellectual developmental disorder 23 is, at its heart, the story of listening closely to families, matching patterns across generations, and using advances in genetics to bring that story into sharper focus.