Microtia With Nasolacrimal Duct Imperforation And Eye Coloboma

Clinical Features

Balikova et al. (2008) studied a large family with autosomal dominant inheritance of microtia and nasolacrimal duct imperforation associated with variable degrees of eye coloboma.

Cytogenetics

High resolution cytogenetic analysis in the family reported by Balikova et al. (2008) revealed an abnormal karyotype 46,XY,add(4)(pter). The cytogenetically visible alteration at 4p16-p15 consisted of 5 copies of a copy number variable region, encompassing a low copy repeat (LCR)-rich sequence. Balikova et al. (2008) demonstrated that the amplicon of approximately 750 kb occurred in exact tandem copies. This was thought to be the first example of an amplified copy number variant (CNV) associated with a mendelian disorder.

Inheritance

The transmission pattern of the disorder in the family reported by Balikova et al. (2008) was consistent with autosomal dominant inheritance.