Rare Case of a Heterozygous Microdeletion 9q21.11-q21.2: Clinical and Genetic Characteristics

Balkan J Med Genet. 2018 Dec 31;21(2):59-62. doi: 10.2478/bjmg-2018-0021. eCollection 2018 Dec.

Abstract

Intellectual disability is affecting 3.0-4.0% of the general population. Copy number variants (CNVs) are a significant cause leading to neurodevelopmental disorders such as intellectual disability, epilepsy, autism spectrum disorders and developmental delay. The use of single nucleotide polymorphism (SNP)-array and array comparative genomic hybridization (aCGH) as diagnostic tools has led to the recognition of new microdeletion/microduplication syndromes associated with neurodevelopmental disorders. It is also useful for further characterization of marker chromosomes. Here, we report a girl with mild intellectual disability and mild facial dysmorphisms. Cytogenetic analysis showed a marker chromosome in some percent of the cells and was followed by SNP-array karyotyping that detected, in addition, a 9655 Mb de novo interstitial deletion at 9q21.1-9q21.2.

Keywords: Deletion at 9q21.1; Interstitial deletion; Single nucleotide polymorphism (SNP)-array.