Two novel mutations in the gene EDAR causing autosomal recessive hypohidrotic ectodermal dysplasia.

INTRODUCTION: Hypohidrotic ectodermal dysplasia (HED) is a human heritable disorder characterized by sparse hair, reduced ability to sweat and hypodontia. The HED exhibits X-linked, autosomal recessive and autosomal dominant mode of inheritance. Mutations in four genes including EDA, EDAR, EDARADD, and WNT10A are known to cause hypohidrotic and anhidrotic ectodermal dysplasia. MATERIALS AND METHODS: Genotyping of both affected and normal individuals of two consanguineous Pakistani families (A, B), showing autosomal recessive HED, was carried out using microsatellite markers linked to EDAR gene on chromosome 2q11-q13. To screen for mutations in the gene EDAR, all of its exons and splice junction were amplified and sequenced directly, using an automated DNA sequencer. RESULTS: Genotyping using microsatellite markers analysis showed linkage of the two families to gene EDAR on chromosome 2q11-2q13. Subsequently, screening of all the 12 exons and splice junctions of gene EDAR revealed a novel missense mutation (c.1163T>C; p.Ile388Thr) in family A and a novel insertion mutation (c.1014insA; p.V339SfsX6) in family B. CONCLUSION: Our findings extend the body of evidence supporting the role of EDAR signaling pathway as a powerful regulator of development of ectodermal appendages.

Dipeptidyl peptidase-4 as a new target of action for type 2 diabetes mellitus: a systematic review.

Type 2 diabetes mellitus is a metabolic disease leading to microvascular and macrovascular complications including coronary artery disease and stroke. Management of diabetes has been challenging, particularly in the presence of the enormous prevalence of obesity. In recent years, various inhibitors of the enzyme dipeptidyl peptidase (DPP)-4 have been developed to treat diabetes. The enzyme DPP-4 cleaves incretins, which, among other functions, stimulate insulin and suppresses glucagon. Inhibition of this enzyme results in an increase in the half-life and the sustained physiologic action of incretins, leading to an improvement in hyperglycemia. One such agent, namely sitagliptin (MK-04,310), has been introduced into the United States market, and another agent, vildagliptin (LAF237), is being used in Europe and elsewhere. This article is intended to evaluate the effectiveness of DPP-4 inhibitors as a therapeutic modality for managing type 2 diabetes. The authors conducted a literature search of various databases to identify the clinical trials involving the DPP inhibitors and concluded that the DPP-4 inhibitors, for example, sitagliptin and vildagliptin, are efficacious for managing diabetes as monotherapy or combination therapy.