Researchers at Signature Genomic Laboratories, which performs diagnostic genetic testing of chromosome abnormalities in individuals with unexplained physical and developmental disabilities, recently showed that microarray analysis can identify small DNA alterations in individuals with Pitt-Hopkins syndrome, a rare and poorly characterized genetic disorder.
Children with Pitt-Hopkins syndrome usually have severe mental retardation, characteristic unusual facial features, increased risk for seizures, and may have breathing disturbances which can lead to cyanosis. Although the syndrome has only recently been characterized in depth, researchers know it is caused by the presence of only one functioning copy of the gene TCF4 on chromosome 18, which results when the other copy of the gene is mutated or missing. Previous studies have suggested the clinical features associated with Pitt-Hopkins syndrome are independent of the type of genetic anomaly.