Families often first notice achalasia microcephaly syndrome when a newborn’s head seems smaller than expected (microcephaly) and feeding is unusually difficult, with coughing, choking, or milk coming back up soon after swallowing. In infancy or early childhood, trouble gaining weight, frequent vomiting, or recurrent chest infections can prompt doctors to check the esophagus, where achalasia—tightening at the lower end that blocks food—may be found. For many, the first signs of achalasia microcephaly syndrome are this combination of a small head size at birth plus early swallowing and feeding problems that don’t improve with typical reflux measures.