ABSTRACT
Studies of genomic copy number variants (CNVs) have identified genes associated with autism spectrum disorder (ASD) and intellectual disability (ID) such as NRXN1, SHANK2, SHANK3 and PTCHD1. Deletions have been reported in PTCHD1 however there has been little information available regarding the clinical presentation of these individuals. Herein we present 23 individuals with PTCHD1 deletions or truncating mutations with detailed phenotypic descriptions. The results suggest that individuals with disruption of the PTCHD1 coding region may have subtle dysmorphic features including a long face, prominent forehead, puffy eyelids and a thin upper lip. They do not have a consistent pattern of associated congenital anomalies or growth abnormalities. They have mild to moderate global developmental delay, variable degrees of ID, and many have prominent behavioral issues. Over 40% of subjects have ASD or ASD-like behaviors. The only consistent neurological findings in our cohort are orofacial hypotonia and mild motor incoordination. Our findings suggest that hemizygous PTCHD1 loss of function causes an X-linked neurodevelopmental disorder with a strong propensity to autistic behaviors. Detailed neuropsychological studies are required to better define the cognitive and behavioral phenotype.
Subject(s)
Autism Spectrum Disorder/diagnosis , Autism Spectrum Disorder/genetics , Intellectual Disability/diagnosis , Intellectual Disability/genetics , Membrane Proteins/genetics , Mutation , Phenotype , Sequence Deletion , Adolescent , Adult , Child , Child, Preschool , Exons , Facies , Female , Humans , Infant , Male , Young AdultABSTRACT
We report on a 7-month-old girl with Smith-Magenis syndrome (SMS) due to a 4.76-Mb deletion of 17p12-17p11.2 detected by array comparative genomic hybridization. She was also affected with a left-sided congenital diaphragmatic hernia (CDH) and cardiac anomalies including an atypical atrioventricular canal defect and a cleft mitral valve. To our knowledge, this is the first reported case of a patient with both SMS and CDH. There are numerous chromosomal regions in which duplications, deletions, inversions, or translocations have been associated with CDH, but none have previously been reported at or close to 17p11.2. We discuss candidate genes for the diaphragmatic defect in this patient. Our case demonstrates that it is important to consider the possibility of SMS in non-isolated cases of diaphragmatic hernia.
