Detection of a novel mutation in the GAA gene in an Iranian child with glycogen storage disease type II

Glycogen storage disease II [GSDII or Pompe disease, OMIM # 232300] is an autosomal recessive hereditary lysosomal disorder. Mutations in the GAA gene usually lead to reduced acid alpha-glucosidase [acid maltase, GAA, OMIM [asterisk] 606800, EC 3.1.26.2] activity, which results in impaired degradation and subsequent accumulation of glycogen within lysosomes. We present an Iranian boy, who was diagnosed with GSDII based upon clinical and biochemical findings. A single adenine insertion [insA] was detected at codon 693 that leads to a predicted premature stop codon at codon 736 in the GAA gene. The parents were heterozygous for the same change. According to the human genome mutation database [www.hgmd.org] and lecture reviews, the detected change is a novel mutation. We suppose that the discovered insertion in the GAA gene might lead to a reduced activity of the gene product. This assumption is in agreement with biochemical and clinical signs in the patient

[ first survey of distribution of inherited deafness patterns in individuals referred to genetic center of Ahvaz welfare organization, Southern Iran]

Deafness is a heterogeneous disorder induced by genetic and environmental factors. It is the most common hereditary sensory-neural disorder that affects 1/1000 to 1/2000 of the newborns. More than 70% of hearing loss cases are caused by genetic disorders, 85% of which result from nonsyndromic autosomal recessive sensory-neural hearing loss. Up to now, more than 100 genes contributing in hearing loss have been determined. Alteration of these genes may result in hearing loss. This study was performed to identify the inheritance patterns of deafness and its relation with ethnicity, gender and consanguineous marriages. In this survey, data from 356 families affected by hearing loss and referred to welfare organization of Ahvaz during the time were collected based on sex, ethnic groups and relativeness. The results state a high frequency of autosomal recessive deafness caused by consanguineous marriages within Arab and non-Arab ethnic groups [p<0.05]. But no significant difference in gender. In conclusion, the high frequency of autosomal recessive deafness among the population with a high frequency of consanguineous marriages is considerable. The dominant pattern of deafness observed in this population was autosomal recessive