Diabetes mellitus por mutación en el gen de glucokinasa: caso clínico / Diabetes mellitus caused by a mutation of glucokinase gene: report of an affected family

Maturity-Onset Diabetes of the Young (MODY) refers to a heterogeneous group of monogenic diabetes. Unlike other types of MODY characterized by genetic defects in transcription factors, MODY 2 is triggered by metabolic alterations caused by mutations of glucokinase (GCK), the first enzyme of the glycolytic pathway. We report a three-generation Chilean family with multiple cases affected with this disease. The index case is a patient who presented severe neonatal hyperglycemia (831 mg/dl, without ketosis) requiring continuous infusion of insulin, which was suspended after 48 hours with normalization of blood glucose. Subsequently, continuous glucose monitoring at 4 months of age revealed 47% of tissue glucose levels above 140 mg/dl, with fasting glucose levels between 120 and 166 mg/dl. The genetic analysis revealed a previously reported mutation in heterozygous state of the GCK gene (c.148C>T; p.His50Tyr). This mutation was also identified in more than one affected relative in the last two generations, with a transmission pattern suggestive of dominant inheritance. GCK gene sequencing led to a correct molecular diagnosis of MODY 2 while bioinformatic analysis indicated the possible molecular causes of the enzyme dysfunction. The knowledge of the molecular diagnosis allowed an adequate medical treatment for this disease.

Neutropenia inducida por propiltiouracilo en paciente con síndrome de Down e hipertiroidismo / Neutropenia induced by propylthiouracil in patient with down syndrome and hyperthyroidism

Se presenta el caso de un paciente de sexo masculino de 10 años de edad, con antecedente de síndrome de Down, que consulta por cuadro de hipertiroidismo compatible con enfermedad de Base-dow-Graves. Recibe tratamiento con propiltiouracilo en dosis de 5 mg/kg/día. Veinte días después de iniciado el tratamiento, desarrolla agranulocitosis secundaria al uso de PTU. Se realiza una revisión sobre el hipertiroidismo en pacientes con síndrome de Down, el tratamiento de esta patología, y las reacciones adversas más frecuentes descritas en relación al uso de PTU.