I. Background: Congenital central hypoventilation syndrome (CCHS) is an extremely rare genetic disorder characterized by autonomic nervous system (ANS) dysregulation caused by mutations in the PHOX2B gene. Here we introduce the first genetic analysis of a CCHS patient in Iran.II. Methods and Results: Genetic analysis of the PHOX2B gene was performed by Sanger sequencing and interpreted using the American College of Medical Genetics and Genomics (ACMG) guideline. The results showed a

more »

... duplication in the exon 3 causing a polyalanine repeat expansion mutation (PARMs) to 27 repeats in the PHOX2B gene (20/27 genotype). The patient's parents were normal for this mutation.III. Conclusions: According to the ACMG guideline, the mutation is a pathogenic one, and it was a denovo mutation in the family. The genetic study can help the family for prenatal diagnosis or pre-implantation diagnosis if the parents have gonadal mosaicism.