Dend Syndrome

DEND syndrome is a very rare, generally severe form of neonatal diabetes mellitus (NDM, see this term) characterized by a triad of developmental delay, epilepsy, and neonatal diabetes.

Epidemiology

Fewer than 40 cases have been reported to date.

Clinical description

DEND syndrome represents the most severe end of the neonatal diabetes mellitus spectrum. Patients have hyperglycemia requiring insulin therapy that presents within 12 months of birth. The associated neurologic features range from mild psychomotor retardation to severe developmental delay. Patients also have therapy-resistant epilepsy and muscle hypotonia. A less severe, intermediate form has been described and is known as iDEND (see this term).

Etiology

DEND syndrome is caused in most cases by gain of channel function mutations in the KCNJ11 gene (11p15.1), encoding a subunit of the ATP-sensitive potassium (KATP) channel. Mutations in this gene also cause permanent neonatal diabetes mellitus (PNDM, see this term). Only 20% of individuals with mutations in this gene develop DEND or the intermediate DEND form. Rare reports of specific mutations in theABCC8 gene (11p15.1) have also been associated with DEND.

Genetic counseling

The pattern of inheritance of DEND syndrome is either de novo mutation, dominant, or very rarely recessive.