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TBR1 is the candidate gene for intellectual disability in patients with a 2q24.2 interstitial deletion
Author(s) -
Palumbo Orazio,
Fichera Marco,
Palumbo Pietro,
Rizzo Renata,
Mazzolla Elisabetta,
Cocuzza Donatella Maria,
Carella Massimo,
Mattina Teresa
Publication year - 2014
Publication title -
american journal of medical genetics part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.064
H-Index - 112
eISSN - 1552-4833
pISSN - 1552-4825
DOI - 10.1002/ajmg.a.36363
Subject(s) - genetics , haploinsufficiency , biology , gene , candidate gene , phenotype , intellectual disability , microcephaly , single nucleotide polymorphism , genotype
Interstitial deletion of 2q24.2 is a rarely described cytogenetic aberration in patients with intellectual disability (ID). Previously reported genotype–phenotype correlation identified a minimum deleted region of 2.65 Mb including 15 genes. Recently, a patient with a de novo 2q24.2 microdeletion of 0.4 Mb encompassing only three genes was described. However, the precise relationship between most deleted genes and the clinical features remains unclear. Here we describe a 12‐year‐old male patient diagnosed with growth retardation and ID. He also showed microcephaly, right palpebral ptosis, scapular winging, and pectus excavatum. Single nucleotide polymorphisms (SNP) array analysis showed a de novo interstitial deletion of 0.122 Mb at 2q24.2 region harboring only TBR1 (T‐box, brain, 1; OMIM: 604616), which encodes a T‐box family transcription factor expressed in post‐mitotic projection neurons and functionally significant in embryologic corticogenesis. This is the first case of a deletion at 2q24.2 involving only TBR1 . This finding narrows the smallest region of overlap (SRO) for deletions in this region and strengthens the previously suggested hypothesis that this gene is a strong candidate for the ID phenotype. The identification of TBR1 as candidate for ID encourages further molecular studies to identify novel mutations to understand the pathogenic effects of its haploinsufficiency. Finally, this report provides a review on 10 2q24.2 microdeletion patients. © 2014 Wiley Periodicals, Inc.