ISSN: 1308-5727 | E-ISSN: 1308-5735
Volume: 16 Issue: 2 Year: 2024

Abstracting & Indexing
Turkish Society for Pediatric Endocrinology and Diabetes
A Case of Diabetes Mellitus Type MODY5 as a Feature of 17q12 Deletion Syndrome [J Clin Res Pediatr Endocrinol]
J Clin Res Pediatr Endocrinol. 2024; 16(2): 205-210 | DOI: 10.4274/jcrpe.galenos.2022.2022-3-2

A Case of Diabetes Mellitus Type MODY5 as a Feature of 17q12 Deletion Syndrome

Hümeyra Yaşar Köstek1, Fatma Özgüç Çömlek1, Hakan Gürkan2, Emine Neşe Özkayın3, Filiz Tütüncüler Kökenli1
1Trakya University Faculty of Medicine, Department of Pediatric Endocrinology, Edirne, Turkey
2Trakya University Faculty of Medicine, Department of Medical Genetics, Edirne, Turkey
3Trakya University Faculty of Medicine, Department of Pediatric Nephrology, Edirne, Turkey

Maturity onset diabetes of the young (MODY) is characterized by noninsulin-dependent diabetes diagnosed before the age of 25 years with an autosomal dominant inheritance. Rare mutations in the hepatocyte nuclear factor-1-beta (HNF1B) gene produce a syndrome that resembles MODY. About half of patients diagnosed with MODY type 5 due to HNF1B variants, carry a whole gene deletion, known as 17q12 deletion syndrome. 17q12 deletion syndrome is a rare chromosomal anomaly and is typified by deletion of more than 15 genes, including HNF1B resulting in kidney abnormalities and renal cysts, a diabetes syndrome and neurodevelopmental or neuropsychiatric disorders. A 12-year-old girl was referred after high blood sugar was detected in the hospital where she presented with polyuria and
polydipsia, which had persisted for one month. Her serum magnesium (Mg) level was low at 1.5 mg/dL (normal value 1.6-2.6) and glycated hemoglobin was 14% (normal value 3.6-5.8) concurrent with a c-peptide of 1.54 ng/mL (normal value 0.8-4). MODY5 was suspected but the NGS gene panel (ABCC8, BLK, CEL, GCK, HNF1A, HNF1B, HNF4A, INS, KCNJ11, KLF11, NEURODD1, PAX4, PDX1, RFX6, ZFP57, GLIS3, FOXP3, NEUROG3, G6PC2) did not identify any abnormality. During follow-up, her serum Mg remained low (1.2 mg/dL) together with elevated urinary Mg excretion at 172.5 mg/day. An HNF1B variant was again suspected in a patient with chronic hypomagnesemia with normal basal C peptide level. Abdominal computed tomography and magnetic resonance imaging revealed a 43 mm diameter, cystic lesion in the head of the pancreas, with agenesis of the pancreatic neck, trunk and tail. Genetic testing using a microarray analysis was subsequently performed and a heterozygous deletion at 17q12, including HNF1B, was detected. In case of clinical suspicion of HNF1B variants, further genetic examination using other techniques such as MLPA and CGH array may be required to detect the variant. This is because deletions and duplications may not be detected using next generation screening panel techniques.

Keywords: MODY5, 17q12 deletion, diabetes mellitus, hypomagnesemia

Hümeyra Yaşar Köstek, Fatma Özgüç Çömlek, Hakan Gürkan, Emine Neşe Özkayın, Filiz Tütüncüler Kökenli. A Case of Diabetes Mellitus Type MODY5 as a Feature of 17q12 Deletion Syndrome. J Clin Res Pediatr Endocrinol. 2024; 16(2): 205-210

Corresponding Author: Hümeyra Yaşar Köstek, Türkiye
Manuscript Language: English
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