A family of Bart-Pumphrey syndrome.

Bart-Pumphrey syndrome (BPS) is an autosomal-dominant disorder characterized by hearing loss, leukonychia, knuckle pads and palmoplantar keratoderma. Two mutations in the extracellular domain of GBJ2 are resposible for this syndrome. To date, less than 10 case reports or clinical series about BPS have been published in the literature. Hearing loss and knuckle pads are the more commonly seen findings of this syndrome. Three generations and six family members with variable findings of knuckle pads, leukonychia, hearing loss and palmoplantar hyperkeratosis were presented in this report. We want to emphasize that dermatogists must be alert during the evaluation of these findings because some findings of this disorder may be vague or absent.

In Silico Study of Human Gap Junction Beta-2 Protein by Homology Modeling

Asp66his, Asp54Lys, and Asp50Asn are mutations in connexin 26 that are observed in the clinic and give rise to autosomal dominant syndromes. They are the result of point mutations in the human gap junction beta-2 gene. In order to investigate the structural mechanism of Bart-Pumphrey Syndrome, Keratitis-Ichthyosis-Deafness Syndrome, and Vohwinkel Syndrome, homology modeling was carried out. Asp66 has direct contact with Asn62 by two hydrogen bonds in the wild-type protein, and in Asp66His, the biggest change observed is a tremendous energy increase caused by hydrogen bond breakage to Asn62. Shifts in the side chain and new hydrogen bond formation are observed for Lys54 compared to the wild-type protein (Asn54) and result in closer contact to Val84. Asp50Asn causes a significant decrease in bond energy, and residual charge reversal repels the ion and metabolites and, hence, inhibits their transportation. Such perturbations are likely to be a factor contributing to abnormal functioning of ion channels, resulting cell death and disease.