Screening program for Waardenburg syndrome in Colombia: Clinical definition and phenotypic variability

Abstract

A screening program to detect Waardenburg syndrome (WS) conducted between 2002 and 2005, among 1,763 deaf individuals throughout Columbia identified 95 affected individuals belonging to 95 families, giving a frequency of 5.38% of WS among the institutionalized deaf population. We confirmed the clinical diagnosis of WS in the 95 propositi and, through the family evaluation, we also identified 45 non-institutionalized affected relatives. Audiologic, ophthalmologic, and genetic studies were performed to confirm the diagnosis. Following the classification of the WS consortium, based on the Waardenburg Index (WI), to define the type of WS. We classified 62.1% of the propositi as WS2 and 37.9% as WS1. We present here the results of the study of clinical manifestations, analyzing the presence, severity, and symmetry of clinical findings among this affected population. Overall, among the 95 propositi, in addition to sensorineural deafness in all, the most frequent features were broad nasal root (58.9%), a first degree relative affected (37.9%), heterochromia irides (36.8%), skin hypopigmentation (31.6%), white forelock (28.0%), intense blue iris (27.4%), synophrys (12.6%), premature graying (10.5%), ptosis of the eyelids (9.5%), and hypoplasia alae nasi (1.1%). The majority of individuals had normal psychomotor development (87%), while the remaining 13% had developmental delay. Among the latter, 9.4% corresponded to WS2 and 3.6% to WS1. Our data confirm an interesting inter- and intrafamilial variability in the phenotypic manifestations as well as extremely variable expression.

Disorders of pigmentation

“…18 There are several rare syndromes in which extracutaneous manifestations accompany the piebaldism. [22][23][24][25][26][27][28] Four major variants of Waardenburg's syndrome have now been described, each one due to the involvement of different genes. [22][23][24][25][26][27][28] Four major variants of Waardenburg's syndrome have now been described, each one due to the involvement of different genes.…”

Paediatric Cochlear Implantation in Patients with Waardenburg Syndrome

“…Waardenburg syndrome (WS) patients account for approximately 2-5% of the congenitally deaf population [Nayak and Isaacson, 2003;Tamayo et al, 2008] and usually express congenital non-progressive SNHI unilater-ally or bilaterally with a severe-to-profound character [Newton, 1990]. The hearing impairment expressed by WS has no typical audiogram shape, can be highly variable and can even be asymmetric [Pingault et al, 2010].…”

A Novel Pathogenic Variant in the MITF Gene Segregating with a Unique Spectrum of Ocular Findings in an Extended Iranian Waardenburg Syndrome Kindred

“…WS1 (OMIM 193500) and WS2 (OMIM 193510) are the most frequent types [Tamayo et al, 2008;Zaman et al, 2015]. WS2 can be distinguished from WS1 by the absence of dystopia canthorum, a lateral displacement of the inner canthi.…”