Mutation in HOXB۱ associated with autosomal recessive hereditary congenital facial palsy

Introduction: Hereditary congenital facial palsy (HCFP) is a rare congenital cranial dysinnervation disorder, recognizable by non-progressive isolated facial nerve palsy(cranial nerve VII). It is caused by developmental abnormalities of the facial nerve nucleus and its nerve. So far, ۴ homozygous mutations have been identified in ۵ unrelatedfamilies (۱۲ patients) with HCFP worldwide. Methods: A large Iranian consanguineous kindred with ۵ members affected by HCFP underwent thorough clinical and genetic evaluation. The candidate gene HOXB۱ was screened and analyzed by Sanger sequencing. As in previous cases, the most remarkable findings in the affected members of the family were mask-like faces, bilateral facial palsy with variable sensorineural hearing loss, and some dysmorphic features. Results: Direct sequencing of the candidate gene HOXB۱ identified a novel homozygous frameshift mutation (c.۲۹۶_۳۰۲del; p.Y۹۹Wfs*۲۰) which segregated with the disease phenotype within the extended family.Conclusions: Our findings expand the mutational spectrum of HOXB۱ involved in HCFP and consolidate the role of the gene in the development of autosomal recessiveHCFP. Moreover, the truncating mutation identified in this family leads to a broadly similar resentation and severity observed in previous patients with nonsense and missense mutations. This study characterizes and defines the phenotypic features of this rare syndrome in a larger family than has previously been reported.

کلیدواژه ها:

HOXB۱ ، Autosomal ، Recessive Hereditary ، Congenital Paralysis.