ABSTRACT
The cause of hearing impairment has not been elucidated in a large proportion of patients. We screened by 1-Mb array-based comparative genomic hybridization (aCGH) 29 individuals with syndromic hearing impairment whose clinical features were not typical of known disorders. Rare chromosomal copy number changes were detected in eight patients, four de novo imbalances and four inherited from a normal parent. The de novo alterations define candidate chromosome segments likely to harbor dosage-sensitive genes related to hearing impairment, namely 1q23.3-q25.2, 2q22q23, 6p25.3 and 11q13.2-q13.4. The rare imbalances also present in normal parents might be casually associated with hearing impairment, but its role as a predisposition gene remains a possibility. Our results show that syndromic deafness is frequently associated with chromosome microimbalances (14-27%), and the use of aCGH for defining disease etiology is recommended.
Subject(s)
Chromosomal Instability/genetics , Hearing Loss/genetics , Child , Child, Preschool , Comparative Genomic Hybridization , Female , Gene Dosage , Humans , Male , SyndromeABSTRACT
We report on two boys, monozygotic twins born to normal and nonconsanguineous parents, presenting with an unusual facial appearance, cortical atrophy, dolichocephaly, short stature, cleft palate, micrognathia, prominent upper central incisors, bilateral Sidney line, minor foot deformities, unstableness in walking, early hypotonia, hyperreflexia, hyperactivity, psychomotor retardation, and severe delay in language development. These manifestations resemble those previously described in the Smith-Fineman-Myers syndrome.
