Molecular and clinical characterization of Waardenburg syndrome type I in an Iranian cohort with two novel PAX3 mutations.
Waardenburg syndrome (WS) is a disease of abnormal neural-crest derived melanocyte development characterized by hearing loss and pigmentary disturbances in hair, eyes and skin. WS is subdivided into four major types, WS1-WS4, where WS1 is recognized by the presence of dystopia canthorum, with PAX3 being the only known gene involved. This study aimed at investigating PAX3 mutations and clinical characteristics of WS1 in a group of Iranian patients. A total of 12 WS1 patients from four unrelated Iranian families were enrolled. Waardenburg consortium guidelines were used for WS1 diagnosis. A detailed family history was traced and a thorough clinical examination was performed for all participants. Furthermore, WS1 patients underwent screening for PAX3 mutations using PCR-sequencing. Dystopia canthorum, broad high nasal root and synophrys were observed in all patients. Early graying, hair discoloration, hypoplastic blue eyes (characteristic brilliant blue iris) and hearing loss were the most common features observed, while heterochromia iridis was the least frequently observed sign among the studied Iranian WS1 patients. Genetic analysis of PAX3 revealed four mutations including c.667C>T, c.784C>T, c.951delT and c.451+3A>C. Two of the four mutations reported here (c.951delT and c.451+3A>C) are being reported for the first time in this study. Our data provide insight into genotypic and phenotypic spectrum of WS1 in an Iranian series of patients. Our results expand the spectrum of PAX3 mutations and may have implications for the genetic counseling of WS in Iran.
Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Nazanin
N
Jalilian
Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran; Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University Of Medical Sciences, Isfahan, Iran.
Mohammad Amin
MA
Tabatabaiefar
Department and Research Center of Otolaryngology, Head and Neck Surgery, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, IR Iran.
Mohammad
M
Farhadi
Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Tayeb
T
Bahrami
Department and Research Center of Otolaryngology, Head and Neck Surgery, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, IR Iran.
Hesam
H
Emamdjomeh
Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: nooridaloii@tums.ac.ir.
Mohammad Reza
MR
Noori-Daloii
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D015331:Cohort Studies; D005260:Female; D056726:Genetic Association Studies; D005817:Genetic Counseling; D005838:Genotype; D006801:Humans; D007223:Infant; D007492:Iran; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors / Q000235:genetics*; D010375:Pedigree; D014849:Waardenburg Syndrome / Q000235:genetics*; D055815:Young Adult
D000072041:PAX3 Transcription Factor; C489409:PAX3 protein, human; D051761:Paired Box Transcription Factors
Hearing loss; Iran; Mutation; PAX3; Waardenburgsyndrome type 1