3q29 Recurrent Deletion

Clinical characteristics 3q29 recurrent deletion is characterized by global developmental delay and/or intellectual disability, and commonly, speech delay, and increased risk for neuropsychiatric disorders (including autism spectrum disorder, anxiety disorder, psychosis, and/or schizophrenia). Other common findings are failure to thrive and feeding problems in infancy that persist into childhood, heart defects (especially patent ductus arteriosus), gastrointestinal disorders (including gastroesophageal reflux disease), and dental abnormalities. To date findings in fewer than 50 affected individuals have been reported. Diagnosis/testing The diagnosis of the 3q29 recurrent deletion is established by detection of the 1.6-Mb heterozygous deletion by chromosomal microarray at the approximate position of chr3:195998129-197623129 in the reference genome (NCBI Build 38). Management Treatment of manifestations: Early speech and language therapy to address speech delays; physical therapy as needed to address fine and gross motor delays; individualized education program (IEP) for school-age children; care by a child psychiatrist/psychologist as needed for neuropsychiatric disorders; feeding therapy and consideration of gastrostomy tube as needed; routine management of dental caries, congenital heart defects, recurrent ear infections. Surveillance: Continued assessment of feeding and nutrition, developmental milestones, cognitive development, and possible neuropsychiatric manifestations. Evaluation of relatives at risk: Parents and older and younger sibs of a proband should be tested for the 3q29 recurrent deletion to encourage close assessment/monitoring of developmental milestones (in children) and monitoring for neuropsychiatric manifestations (in children and adults). Genetic counseling The 3q29 recurrent deletion is inherited in an autosomal dominant manner. Although most deletions are de novo, inherited deletions have been reported. If the 3q29 recurrent deletion identified in the proband is not identified in one of the parents, the risk to sibs is low (