Tassano Elisa, Ronchetto Patrizia, Calcagno Annalisa, Fiorio Patrizia, Gimelli Giorgio, Capra Valeria, Scala Marcello
Laboratorio di Citogenetica, Istituto Giannina Gaslini, 16147 Genova, Italy.
J Genet. 2019 Jun;98(2).
The 16p12.2 chromosome band contains three large segmental duplications: BP1, BP2 and BP3, providing a substrate for recombination and recurrent chromosomal rearrangements. The '16p12.2 microdeletion' is a recurrent deletion comprised between BP2 and BP3, associated with variable clinical findings. We identified a heterozygous 16p12.2 microdeletion spanning between BP1 and BP2 in a child evaluated for short stature and mild dyslexia. Unexpectedly, the mother carried the same deletion in the homozygous state and suffered from severe hearing loss. Detailed family history revealed consanguinity of the maternal grandparents. The 16p12.2 microdeletion is a rare condition and contains only three genes: , and of which the is considered responsible for DFNB22 hearing loss (MIM: 607039) under its homozygous condition. A number of OTOA mutations have been described, whereas very few cases of a 16p12.2 microdeletion similar to that observed in our family have been reported. In conclusion, we describe a rare 'distal 16p12.2microdeletion' widening the phenotypic spectrum associated with the recurrent 16p12.2 microdeletion and support the causative role of microdeletion in hearing impairment.
16p12.2染色体带包含三个大的节段性重复:BP1、BP2和BP3,为重组和复发性染色体重排提供了底物。“16p12.2微缺失”是一种复发性缺失,位于BP2和BP3之间,与多种临床症状相关。我们在一名因身材矮小和轻度诵读困难接受评估的儿童中发现了一个杂合的16p12.2微缺失,其范围在BP1和BP2之间。出乎意料的是,母亲呈纯合状态携带相同的缺失,并患有严重听力损失。详细的家族史显示外祖父母是近亲。16p12.2微缺失是一种罕见病症,仅包含三个基因: 、 和 ,其中 在纯合状态下被认为是导致DFNB22听力损失(MIM:607039)的原因。已经描述了许多OTOA突变,而与我们家族中观察到的类似的16p12.2微缺失病例报告极少。总之,我们描述了一种罕见的“远端16p12.2微缺失”,拓宽了与复发性16p12.2微缺失相关的表型谱,并支持微缺失在听力障碍中的致病作用。