Dysmorphic features,frontal cerebral cavernoma,and hyperglycemia in a girl with a De Novo deletion of 7.23 mb in region 7p13-p12.1

We describe the case of a 7-year-old girl referred to our diabetes unit for hyperglycemia associated with facial dysmorphic features,intellectual disability,and cerebral cavernomas. based on presence of anti islet antigen-2 (ia2) antibodies and a human leukocyte antigen of dr3/dr4/dq2,the patient was initially diagnosed to be a case of type 1 diabetes mellitus. at follow-up,the very good metabolic control on a low insulin dose and negative ia2 antibodies led to a suspicion of glucokinase (gck)-related maturity-onset diabetes of the young (mody 2). this suspicion was substantiated in multiplex ligation-dependent probe amplification (mlpa) which showed a heterozygous gck deletion (exons 1 to 12). however,the patient’s parents did not have such a deletion and were clinically euglycemic. given the clinical picture and the mlpa findings,array based comparative genomic hybridization was performed showing a monoallelic deletion of 7.23 mb in the short arm of chromosome 7 (7p13-p12.1). the deleted intervals contain 39 genes listed in the online mendelian inheritance in man list,including gck associated with mody 2,ccm2 associated with type 2 cerebral cavernous malformations,igfbp-3 associated with decrease in postnatal growth,and ogd associated with alpha-ketoglutarate dehydrogenase deficiency,with cognitive impairment and movement abnormalities. this previously unreported deletion was considered to explain the clinical picture of the patient. also,the findings suggest that 7p13-p12.1 contains genes involved in intellectual disability and craniofacial development. © 2017 by turkish pediatric endocrinology and diabetes society.