Maturity onset diabetes of young type 2 due to a novel de novo GKC mutation.
Maturity Onset Diabetes of Young (MODY) is a heterogeneous group of monogenic disorders that result in β-cell dysfunction, with an estimated prevalence of 1%-2% in industrialized countries. MODY generally occurs in non-obese patients with negative autoantibodies presenting with mild to moderate hyperglycemia. The clinical features of the patients are heterogeneous, depending on the different genetic subtypes. We pretend to report a case of MODY type 2 caused by a novel de novo CGK mutation, highlighting the importance of the differential diagnosis in pediatric diabetes. A 13-year-old, healthy and non-obese girl was admitted for investigation of recurrent hyperglycemia episodes. She presented with persistent high levels of fasting blood glycemia (> 11.1 mmol/L) and had no familial history of diabetes. The blood glucose proﬁle revealed an impaired fasting glucose of 124 mg/dL (6,9 mmol/L) with a normal oral glucose tolerance test. Fasting insulinemia was 15 mg/dL (90.1 pmol/L), HOMA-IR was 3.9 and hemoglobin A1c was 7.1%. Pancreatic autoantibodies were negative. Genetic testing identified a novel missense heterozygous mutation in exon 5 of GCK gene c.509G > T (p.Gly170Val), not present on the parents. This result established the diagnosis of MODY type 2. Clinical identification of patients with MODY remains a diagnostic challenge, especially when familial history is absent. Molecular diagnosis is very important for establishing an individualized treatment and providing a long term prognosis for each type of MODY.
Centro Hospitalar Barreiro Montijo, Hospital Nossa Senhora do Rosário, Portugal.
Paula
P
Afonso
Centro Hospitalar Barreiro Montijo, Hospital Nossa Senhora do Rosário, Portugal.
Nélia
N
Ferraria
Centro Hospitalar Barreiro Montijo, Hospital Nossa Senhora do Rosário, Portugal.
Alexandre
A
Carvalho
Centro Hospitalar Barreiro Montijo, Hospital Nossa Senhora do Rosário, Portugal.
Sofia Vidal
SV
Castro
D000293:Adolescent; D001786:Blood Glucose / Q000032:analysis; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis* / Q000235:genetics; D003937:Diagnosis, Differential; D005215:Fasting; D005260:Female; D005820:Genetic Testing; D005941:Glucokinase / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D006943:Hyperglycemia / Q000097:blood; D007328:Insulin / Q000097:blood; D020125:Mutation, Missense / Q000235:genetics*
D001786:Blood Glucose; D007328:Insulin; D005941:Glucokinase