Larsen syndrome is a rare genetic condition that affects joints, bones, and the face. People with Larsen syndrome often have very flexible joints, frequent dislocations, and flat midface features. Signs are present from birth and the condition is lifelong, but severity varies. Many living with Larsen syndrome receive orthopedic care, physical therapy, and sometimes surgery, and breathing support may be needed in infancy. The outlook can be good with careful management, but risks like airway and spine problems mean regular follow-up is important.
Overview
Larsen syndromeSymptoms
Larsen syndrome causes multiple joint dislocations, loose joints, clubfeet, and distinctive facial features; often noticed before birth or at delivery. Spine abnormalities and breathing problems can occur. Some have hearing issues and delayed motor milestones.
Outlook and prognosis
Most people with Larsen syndrome grow up to lead full lives, especially with early orthopedic care and physical therapy. Joint stability, spine health, and airway safety guide long‑term outlook, and many surgeries are planned—not emergencies—to improve comfort and function. Regular monitoring helps prevent complications and supports school, work, and family goals.
Causes and risk factors
Larsen syndrome is caused by changes in the FLNB gene; usually autosomal dominant; inherited from an affected parent or arises new. Family history increases risk. No known environmental triggers; severity varies, with rare recessive forms reported.
Genetic influences
Genetics play a central role in Larsen syndrome. Most cases result from pathogenic changes in the FLNB gene, often inherited in an autosomal dominant pattern, though new (de novo) variants occur. Rarely, autosomal recessive forms exist, influencing severity and recurrence risk.
Diagnosis
Doctors often recognize Larsen syndrome from clinical features, especially multiple joint dislocations and characteristic facial or limb findings. X-rays and other imaging assess bones and joints. Genetic diagnosis of Larsen syndrome uses FLNB gene testing, sometimes including prenatal ultrasound.
Treatment and drugs
Treatment for Larsen syndrome centers on protecting mobility, easing pain, and supporting daily function. Care often combines expert orthopedic surgery to stabilize joints and spine, bracing or casting, targeted physical therapy, and careful airway and hearing management. Regular follow-up helps adjust supports as children grow.
Symptoms
Day to day, many families first notice differences in how a newborn’s joints move or how the face looks, and sometimes breathing sounds noisier than expected. Parents may see early features of Larsen syndrome such as joints that sit out of place at birth, foot shape differences, and a flatter midface. Features vary from person to person and can change over time. Because Larsen syndrome affects the skeleton and soft tissues from birth, the mix of signs can range from very mild to more complex.
Hips, knees, or elbows can be out of place at birth or move too easily. In medical terms, this is multiple large-joint dislocations; in everyday life, it shows up as joints that slip or sit out of place. Casts, braces, or surgery are sometimes used to improve alignment.
Many people with Larsen syndrome have very flexible joints that bend further than usual. This can make standing, writing, or sports tiring and raise the chance of sprains. Supportive shoes, splints, or therapy can help joints feel more stable.
Early on, this might look like feet that turn in (clubfoot) or feel flat and wide. These shapes can make shoe fit tricky and change how a child stands or walks. Treatments often include stretching, casting, or surgery.
A flatter midface, wide-set eyes, and a small nasal bridge are common. These facial traits are part of Larsen syndrome’s look and do not affect learning or personality.
How people usually first notice Larsen syndrome?
Many families first notice something unusual before or at birth: a prenatal ultrasound may show joints that look out of place, such as knees or hips, or a baby is born with obvious large-joint dislocations and very flexible joints. Doctors may also spot features like a flat-looking midface, widely spaced eyes, or clubfeet, and X-rays can reveal characteristic bone changes, leading to the first signs of Larsen syndrome being recognized in the newborn period. Sometimes it’s picked up a little later in infancy when joints seem unstable, the neck appears unusually mobile, or there are breathing or feeding difficulties linked to airway or spine involvement—prompting evaluation for how Larsen syndrome is first noticed.
Types of Larsen syndrome
Larsen syndrome has a few recognized clinical variants, mostly defined by the specific gene change involved. These variants can look similar at birth—often with joint dislocations and characteristic facial features—but differ in severity, spine involvement, and risks like breathing issues. Symptoms don’t always look the same for everyone. When reading about types of Larsen syndrome, it helps to know that FKBP14-related cases tend to involve more muscle and hearing features, while FLNB-related cases span a broader range of bone and joint findings.
FLNB classic type
This is the most common variant, tied to changes in the FLNB gene. Many have multiple large‑joint dislocations at birth, distinctive facial features, and flexible joints. Spine differences and clubfeet are common, and severity can range from mild to significant.
FLNB severe perinatal
A rarer, life‑threatening form linked to certain FLNB changes. Newborns may have very small chest size, severe airway issues, and underdeveloped lungs. Many do not survive the newborn period despite intensive care.
FKBP14-related type
Caused by changes in the FKBP14 gene, sometimes called an EDS‑like Larsen variant. People often have joint laxity, muscle weakness, and curvature of the spine, and hearing loss can occur. Bone features may be milder than in classic FLNB cases.
Autosomal recessive type
Reported in a few families with features overlapping classic Larsen syndrome. Joint dislocations and foot differences are present, but inheritance involves two non‑working copies of a gene. Genetic testing helps confirm this rare variant and guides family planning.
What genetics can tell you about symptoms
Some people with Larsen syndrome inherit changes in genes like FLNB that disrupt how connective tissues form, leading to joint laxity, frequent dislocations, and distinctive facial features. Certain variants can also affect bone growth and spine alignment, causing short stature and scoliosis.
Causes and risk factors
Larsen syndrome is usually caused by a change in the FLNB gene.
This change can be inherited from a parent with Larsen syndrome, or it can occur for the first time in a child.
If a parent has Larsen syndrome, each pregnancy has about a 50% chance to inherit the gene change.
No lifestyle choice or environmental exposure is known to cause it, but features and severity can differ a lot between people.
Knowing the risks can help you feel more in control, and it can guide early checks for early symptoms of Larsen syndrome.
Environmental and biological risk factors
If you're planning a pregnancy or already pregnant, it's natural to wonder what you can control. Larsen syndrome is present from birth and mainly stems from internal biological factors rather than day-to-day choices during pregnancy. Doctors often group risks into internal (biological) and external (environmental). For risk factors for Larsen syndrome in pregnancy, there are no proven environmental triggers, and clinicians mostly consider general pregnancy health and a few age-related factors.
Conception at an older paternal age is linked to a higher chance of brand-new changes when sperm cells are made. This slightly raises the chance of rare conditions present from birth, including Larsen syndrome. The absolute risk remains very low.
No specific pregnancy exposures such as radiation, heavy metals, or common air pollutants are known to cause Larsen syndrome. Studies so far have not shown a consistent environmental trigger.
Health issues like poorly controlled preexisting diabetes can raise overall risk of birth differences. A direct link to Larsen syndrome has not been shown. Good prenatal care helps manage general risks.
Uterine crowding or breech position can lead to isolated joint dislocations in newborns. These positional effects do not cause Larsen syndrome. When many joints are affected from birth, a deeper connective-tissue difference is usually involved.
Genetic risk factors
Genetic changes in the FLNB gene are the main cause of Larsen syndrome, usually passed in an autosomal dominant pattern. Some cases arise as a new (de novo) change with no previous family history. Some risk factors are inherited through our genes. Understanding the specific gene change can guide family planning and monitoring for early symptoms of Larsen syndrome.
FLNB gene variants: Most people with Larsen syndrome have a change in the FLNB gene, which helps shape developing bones and joints. These changes disrupt normal cartilage and bone growth. The exact variant can influence which features are most prominent.
Dominant inheritance: When a parent carries an FLNB change, each child has a 50% chance of inheriting it. This pattern is called autosomal dominant. Features may be milder or more obvious from one family member to another.
De novo changes: Many with Larsen syndrome are the first in their family affected. The gene change happens for the first time in the egg, sperm, or early embryo. Parents without the change usually have a low chance of another affected child.
Parental mosaicism: Rarely, an unaffected parent carries the FLNB change in a small portion of their eggs or sperm. This can slightly raise the chance of having another child with Larsen syndrome. Specialized tests can sometimes look for this.
Variable expression: Signs and severity vary widely even within the same family. People with the same risk factor can have very different experiences. This makes it hard to predict exactly how Larsen syndrome will look in any one person.
FLNB condition spectrum: Different FLNB changes can cause related skeletal conditions with overlapping features. Some variants lead to more severe differences, while others are milder. Knowing the exact change helps tailor care and counseling.
Recessive look-alikes: Rare, autosomal recessive conditions can resemble Larsen syndrome but are caused by different genes. These require both parents to carry the same hidden change. Genetic testing helps tell them apart.
Genetic testing: Testing the FLNB gene can confirm the genetic cause. In some cases, genetic testing can give a clearer picture of your personal risk. Results can guide family screening and planning.
Lifestyle risk factors
Lifestyle habits do not cause Larsen syndrome, but they can shape joint stability, pain, mobility, and complication risk. Below are lifestyle risk factors for Larsen syndrome tied to daily activity, nutrition, and habits. Understanding how lifestyle affects Larsen syndrome can help tailor routines with your care team.
Jumping, contact sports, and sudden pivots can increase dislocations or subluxations in hypermobile joints. Low-impact options like swimming or cycling build strength with less joint strain.
Regular, tailored strengthening and proprioception work improves joint stability and function. Skipping sessions can lead to stiffness, pain, and higher dislocation risk.
Excess body weight magnifies load on lax hips, knees, and ankles, worsening pain and instability. Maintaining a healthy weight reduces joint stress and aids mobility.
Using braces or splints as prescribed and avoiding extreme ranges of motion helps protect unstable joints. Repetitive strain and heavy lifting increase injury and dislocation risk.
Risk prevention
Larsen syndrome is genetic, so you can’t prevent it entirely, but you can lower the chance of complications and protect long‑term function. For many, this means protecting unstable joints, guarding the neck, and planning care around breathing and mobility needs. Recognizing early symptoms of Larsen syndrome and getting timely support can help avoid injuries and stiffness. Different people need different prevention strategies—there’s no single formula.
See an orthopedic team regularly to track joint position and growth. Early changes can be treated before they cause pain or lasting damage.
Ask about imaging of the upper spine, especially before sports or surgery. A supportive collar or activity limits may protect the neck if it’s unstable.
Gentle, regular exercises help stabilize joints and improve balance. A therapist can show safer ways to move and protect loose joints.
Braces, splints, or custom shoes can reduce dislocations during daily activities. They also help conserve energy and limit swelling after movement.
Transmission
Larsen syndrome is not contagious—you can’t catch it or pass it on through everyday contact, droplets, or blood. Most cases are autosomal dominant, which describes how Larsen syndrome is inherited: a parent living with the condition has a 50% chance of passing it to each child. Sometimes a child is the first in the family to have Larsen syndrome because of a new genetic change; when neither parent is affected, the chance of it happening again is usually low, though rarely a parent may carry the change in some egg or sperm cells only. Very rare recessive forms have been reported in certain groups, where both parents—typically healthy carriers—each pass on the nonworking gene.
When to test your genes
Consider genetic testing if you have features of Larsen syndrome, a family history of it, or joint dislocations, distinctive facial features, or spinal differences without a clear cause. Testing is also helpful before pregnancy or during pregnancy when ultrasound suggests skeletal differences. Results can guide care plans, surveillance, and family planning.
Diagnosis
In newborns and children, signs often include joints that seem unusually flexible or easily dislocated, a flatter midface, and concerns about neck stability. Parents may first notice that diaper changes or gentle lifts trigger a joint that slips out of place. Getting a diagnosis is often a turning point toward answers and support. Doctors confirm the genetic diagnosis of Larsen syndrome by combining a careful exam with imaging and, when needed, genetic testing.
A pediatric specialist looks for multiple joint dislocations, flexible joints, characteristic facial features, and foot or hand differences. They also check breathing, feeding, and neck stability because these can signal higher-risk features.
X-rays survey the shoulders, elbows, hips, knees, hands, feet, and spine for patterns typical of Larsen syndrome. These imaging findings help distinguish it from other conditions with joint laxity or dislocations.
Imaging of the upper spine (cervical X-ray, CT, or MRI) looks for small or misaligned bones and instability. This is important to identify risks to the spinal cord and guide safety planning before surgeries or therapies.
A blood or saliva test can look for changes in the FLNB gene linked to Larsen syndrome. Finding a disease-causing variant confirms the diagnosis and can inform family planning.
Stages of Larsen syndrome
Larsen syndrome does not have defined progression stages. It’s present from birth, and while features can shift as a child grows, it doesn’t follow a step‑by‑step worsening pattern. Diagnosis typically relies on a physical exam, imaging such as X‑rays, and sometimes genetic testing for changes in the FLNB gene; early symptoms of Larsen syndrome may include multiple joint dislocations noticed soon after birth. Different tests may be suggested to help confirm the diagnosis and guide monitoring of the spine, hips, knees, and airway over time.
Outlook and prognosis
Many living with Larsen syndrome think about how mobility, breathing, or joint pain might change over time. The outlook is not the same for everyone, but day-to-day comfort often improves when hip, knee, or foot alignment is addressed early and braces or surgery reduce strain. Some people with Larsen syndrome have mild joint laxity and lead active adult lives with tailored exercise and periodic orthopedics visits; others need ongoing physical therapy, custom supports, or repeat surgeries as they grow. Early care can make a real difference in preventing repeat dislocations and protecting the spine.
Looking at the long-term picture can be helpful. Children with significant airway or spine involvement usually need closer follow‑up; stabilizing the neck and monitoring the windpipe lowers the risk of breathing emergencies. Most people reach adulthood, and life span is generally near typical when serious airway issues and cervical spine instability are identified and treated. The highest mortality risk tends to cluster in infancy and early childhood if severe airway collapse, heart defects, or untreated neck instability are present, but this risk drops substantially with modern care and planned anesthesia.
Over time, most people with Larsen syndrome find a steady rhythm of care—routine imaging of the neck, joint protection, and pain management as needed. In medical terms, the long-term outlook is often shaped by both genetics and lifestyle. For adults, arthritis and early fatigue around large joints are common, but strengthening the muscles around loose joints can ease symptoms and delay wear. Talk with your doctor about what your personal outlook might look like, and ask how early symptoms of Larsen syndrome—like frequent joint popping or new neck pain—should be handled to prevent setbacks.
Long-term effects
Larsen syndrome is a lifelong genetic condition, and its long-term picture centers on the joints, spine, airway, and growth. Most people reach adulthood, though the degree of mobility and comfort varies from person to person. Long-term effects vary widely, and many live active lives with the right supports around them. Some features change with growth, especially during childhood and the teen years, then tend to settle in adulthood.
Loose joints can continue to slip out of place over the years. Early symptoms of Larsen syndrome often include multiple dislocations that later translate into ongoing instability.
The upper neck bones can be unstable, which raises the lifelong risk of spinal cord compression. This can lead to numbness, weakness, or balance changes if the cord is affected.
Curves in the spine may appear in childhood and can progress during growth. These curves can affect posture and sometimes limit lung expansion.
Misaligned joints tend to wear down faster, leading to arthritis at younger ages. Stiffness and chronic joint pain can build gradually over time.
How is it to live with Larsen syndrome?
Living with Larsen syndrome often means planning around joint laxity and frequent dislocations—simple moves like standing from a chair, reaching overhead, or walking on uneven ground can take extra time and care. Many people use braces, custom shoes, or mobility aids, and schedule regular visits with orthopedic and rehabilitation teams; fatigue and pain can flare after activity, so pacing and recovery days matter. Family, friends, and coworkers may help with transportation, lifting, or child care, and clear communication about limits and safety can prevent injuries and ease stress for everyone. With adaptive tools, physical therapy, and a supportive network, daily life becomes more predictable, and goals at school, work, and home remain very achievable.
Treatment and drugs
Treatment for Larsen syndrome focuses on improving movement, protecting joints, and supporting breathing and daily function. Care usually involves a team: orthopedics for joint dislocations and spine issues, physical and occupational therapy to build strength and flexibility, and, when needed, bracing or custom footwear to stabilize ankles, knees, or hips. Surgery may be recommended for persistent joint dislocations, severe scoliosis, or airway problems; timing depends on age, growth, and how symptoms affect daily life. Pain is managed with standard pain relievers and anti‑inflammatory medicines, and some may benefit from short-term muscle relaxants; a doctor may adjust your dose to balance benefits and side effects. Alongside medical treatment, lifestyle choices play a role, including safe activity plans, respiratory support if breathing is affected (such as CPAP or occasional oxygen), and regular follow-up to watch for changes as children grow or as adults’ needs shift.
Non-drug treatment
Non-drug care for Larsen syndrome focuses on protecting joints, supporting breathing and feeding, improving mobility, and building day-to-day independence across childhood and adulthood. Early symptoms of Larsen syndrome—like frequent joint dislocations or feeding trouble in infancy—often point to therapies that can start right away. Non-drug treatments often lay the foundation for safety and function, with surgery or medicines added only when needed. Plans are tailored, since joint and spine differences vary from person to person.
Gentle, targeted exercises build strength and protect unstable joints. Therapists teach safe ways to move and prevent repeat dislocations.
Skills training helps with dressing, writing, eating, and daily tasks. Adaptive tools and joint-protection techniques reduce strain and fatigue.
Custom splints or braces help hold joints in safer positions. They can improve alignment, reduce pain, and lower the chance of dislocation.
Walkers, crutches, or wheelchairs support safe movement at home, school, and outdoors. Proper fitting reduces falls and joint stress.
Your genes may have an impact on how drugs work for you
Most pain medicines, muscle relaxants, and anesthetics used in Larsen syndrome care can work differently depending on gene variants that change how fast your body processes drugs or how sensitive your receptors are. Pharmacogenetic testing and careful dose adjustments help match treatment to you.
Pharmacological treatments
Medicines for Larsen syndrome focus on easing pain, calming inflammation, protecting bone health, and supporting recovery around surgeries. Drugs that target symptoms directly are called symptomatic treatments. Early symptoms of Larsen syndrome such as tender, swollen joints or muscle spasms may improve with the right mix of pain relievers and anti‑inflammatory medicines. Your team will tailor choices to age, other health conditions, and how your body responds.
Acetaminophen (paracetamol) is often tried first for day‑to‑day joint pain and has fewer stomach side effects than anti‑inflammatories. First-line medications are those doctors usually try first, based on safety and how well they work for most people. Stay within the daily dose and avoid if there is significant liver disease.
Ibuprofen, naproxen, or celecoxib can reduce joint swelling and pain during flares of Larsen syndrome. They can irritate the stomach or affect kidneys and blood pressure, so the lowest effective dose for the shortest time is preferred. A stomach protector such as omeprazole may be added if used regularly.
Gabapentin, pregabalin, or duloxetine can help if nerve-type pain develops from joint instability or after surgery. Dosing may be increased or lowered gradually to balance relief with side effects like sleepiness or dizziness. These medicines are usually added when pain has burning, tingling, or shooting qualities.
Baclofen or tizanidine may ease muscle spasms that sometimes follow dislocations or procedures in Larsen syndrome. They can cause drowsiness or low blood pressure, so short courses and night-time dosing are common. Avoid combining with other sedating medicines unless advised.
Genetic influences
For most people, Larsen syndrome is linked to a change in a gene called FLNB (filamin B). A change in a gene (mutation or variant) can sometimes affect health. If a parent has this change, each child has about a 50% chance of inheriting it; in many others, the change is new in the child, so there’s no prior family history. Rarely, Larsen syndrome can also result from other inheritance patterns in which parents without symptoms each carry a silent change and two copies are needed for the condition to appear. Even within the same family, the severity and features can differ, so genetic results can’t predict the exact course or early symptoms of Larsen syndrome. Testing for FLNB and related genes can confirm the cause and inform pregnancy planning and screening of relatives, and meeting with a genetic counselor can help you understand options.
Is Larsen syndrome genetic?
Genetics play a central role in Larsen syndrome. Most cases result from pathogenic changes in the FLNB gene, often inherited in an autosomal dominant pattern, though new (de novo) variants occur. Rarely, autosomal recessive forms exist, influencing severity and recurrence risk.
Pharmacogenetics—how genetics influence drug effects
When planning care for Larsen syndrome, your genetic diagnosis mostly guides the team’s overall strategy—what needs surgery, how to protect the neck and airway, and which joints to target—rather than pointing to a specific drug. Knowing it’s Larsen syndrome signals possible cervical spine and airway fragility, so anesthesia is planned with extra care, but the gene change itself does not currently dictate a unique anesthetic medicine. The medicines people use are common ones—pain relievers, anti‑inflammatory drugs, muscle relaxants, and sometimes blood thinners after surgery—and here general drug–gene differences can matter. Differences in liver‑enzyme genes can affect how well codeine or tramadol relieve pain, how you handle celecoxib or certain anti‑inflammatory drugs, and your risk of side effects. Alongside medical history and current medications, genetic testing can sometimes identify how your body handles certain pain medicines or blood thinners, which helps your team adjust the dose or choose alternatives. Your care team will still base decisions on your overall health—age, kidney and liver function, prior surgeries, rehabilitation goals—so genetics complements, rather than replaces, clinical judgment in pain management in Larsen syndrome.
Interactions with other conditions
For people with Larsen syndrome, other health issues can change how the bones, joints, airway, heart, and nerves are managed. Day-to-day, it can feel like one health issue amplifies the other. Respiratory conditions such as asthma, frequent chest infections, or sleep apnea can worsen airway fragility seen in Larsen syndrome and increase the chance of breathing trouble during a cold or after surgery. Heart differences that sometimes occur with Larsen syndrome, like a small hole in the heart, may interact with lung problems to raise strain during activity and influence which pain or anesthesia medicines are safest. Because the neck and upper spine can be unstable, conditions that affect balance or muscle tone can raise the risk of falls or nerve injury, so careful positioning and tailored physical therapy matter. Obesity and low bone density can add stress to already loose joints in Larsen syndrome, speeding joint wear and slowing recovery after injuries. If hearing loss or frequent ear infections are present, coordinating hearing support with orthopedic and airway care helps protect speech, learning, and overall quality of life.
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 families in which several children were born with very flexible joints, feet that turned inward, or knees that bent the “wrong” way, then grew up to need braces or surgeries. Midwives and surgeons noted newborns with dislocated hips, elbows, or knees who later walked with a careful, practiced gait. These everyday observations set the stage for what is now known as Larsen syndrome.
First described in the medical literature as a pattern of multiple large-joint dislocations with distinctive facial features in the 1950s by Loren J. Larsen and colleagues, the condition was initially defined by what doctors could see: joint positions at birth, bone shape on X‑rays, and how often surgery was needed. Over time, descriptions became more precise as clinicians recognized that some people with Larsen syndrome had very mild signs—loose joints and subtle facial differences—while others had more complex bone changes, spinal issues, or breathing concerns after birth.
As medical science evolved, specialists realized that similar-looking joint problems could have different causes. Careful follow-up across childhood and adulthood showed that many living with Larsen syndrome led active lives with tailored orthopedic care, while a smaller group needed close monitoring of the spine and airway. These insights helped separate Larsen syndrome from other conditions that also cause joint laxity and dislocations.
Advances in genetics clarified the picture further. In the early 2000s, researchers linked many cases of Larsen syndrome to changes in a gene that helps cartilage and bone form properly, confirming why joints could be unstable and bones shaped differently before birth. Later, rare forms with different inheritance patterns were identified, explaining why some families saw the condition pass from one generation to the next while others had a single, unexpected case.
With each decade, imaging and surgical techniques improved, and newborn care became safer. This shifted the outlook for infants with early symptoms of Larsen syndrome, especially those with airway or spinal concerns. Today, diagnosis blends the older clinical signs—like large-joint dislocations and characteristic bone findings on X‑ray—with genetic testing to guide care and family planning.
Despite evolving definitions, the throughline has stayed the same: careful observation of joints, bones, and breathing from birth onward, matched with supportive treatments that reduce pain and protect function. Knowing the condition’s history helps explain why care teams still look closely at the spine and airway, even when joints are the most visible issue, and why family history remains a key part of the conversation.