Open Access Case report

Type II diabetes and impaired glucose tolerance due to severe hyperinsulinism in patients with 1p36 deletion syndrome and a Prader-Willi-like phenotype

Stefano Stagi14*, Elisabetta Lapi2, Marilena Pantaleo2, Francesco Chiarelli3, Salvatore Seminara1 and Maurizio de Martino1

Author Affiliations

1 Health’s Sciences Department, University of Florence, Anna Meyer Children’s University Hospital, Florence, Italy

2 Genetics and Molecular Medicine Unit, Anna Meyer Children’s University Hospital, Florence, Italy

3 Department of Paediatrics, University of Chieti, Chieti, Italy

4 Paediatric Endocrinology Unit, Anna Meyer Children’s University Hospital, viale Pieraccini 24, Florence 50139, Italy

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BMC Medical Genetics 2014, 15:16  doi:10.1186/1471-2350-15-16

Published: 30 January 2014



Deletion of the subtelomeric region of 1p36 is one of the most common subtelomeric deletion syndromes. In monosomy 1p36, the presence of obesity is poorly defined, and glucose metabolism deficiency is rarely reported. However, the presence of a typical Prader-Willi-like phenotype in patients with monosomy 1p36 is controversial.

Case presentation

In this report, we describe two female patients, one who is 6 years 2 months of age and another who is 10 years 1 month of age, both referred to our hospital for obesity and a Prader-Willi-like phenotype. These patients presented with severe obesity (body mass index [BMI] was 26.4 and 27.7, respectively), hyperphagia and developmental delay. Analysis of basal hormone levels showed normal thyroid function and adrenal function but considerable basal hyperinsulinism (the insulin levels were 54.5 and 49.2 μU/ml, respectively). In patient 1, glycaemia was 75 mg/dl (HOMA-R 10.09), and the HbA1c level was 6.1%; in patient 2, glycaemia was 122 mg/dl, and the HbA1c level was 6.6% (HOMA-R 14.82). An oral glucose tolerance test demonstrated impaired glucose tolerance and diabetes mellitus with marked insulin resistance (the peak insulin level for each patient was 197 and 279 μU/mL, respectively, while the 120’ insulin level of each patient was 167 and 234 μU/mL, respectively).


some patients with monosomy 1p36 may show Prader-Willi-like physical and physiologic characteristics such as obesity and hyperinsulinism with impaired glucose metabolism, which can cause type II diabetes mellitus. Further studies are necessary to evaluate these findings.

Monosomy 1p36; Deletion 1p36; Developmental delay; Mental retardation; Seizures; Obesity; Hyperinsulinism; Impaired glucose tolerance; Hyperphagia; Prader-Willi-like phenotype