Hereditary non-syndromic hearing loss: influence of different variables

Non-syndromic hearing loss [NSHL] was studied in twenty-five patients using a clinical, audiological, cytogenetic and neurobiochemical evaluation. The study group was divided into five subgroups according to severity of hearing loss. Positive parental consanguinity was present in 84% of cases and similarly affected family members were present in 76%. All patients had no congenital malformations and were not dysmorphic. Patients possibly exposed to environmental factors were excluded from the study. Abnormal karyotyping was present in three cases, one case showed chromosome 15p 4, another case showed chromosomal del 11q22.1 and in the third case [47,XY] there was marker chromosome 15. Fluorescence in situ Hybridization [FISH] technique was performed on the case which showed marker. The study group showed significant lowering of five plasma amino acid levels [glutamic acid, aspartic acid, histidine, 3-methylhistidine and carnosine]. There was significant correlation between severity of hearing loss and each of the following: patient's age, glutamic acid, aspartic acid, 3-methylhistidine and carnosine. Identification of NSHL early after birth, as well as, amino acid screening is essential, to allow for faster therapeutic intervention and proper genetic counseling

cytogenetice and immunologic studies in recurrent fetal losses.

The aim of this study was to evaluate the cytogenetic and immunologic role in human reproduction. The study included 158 women with history of repeated fetal losses, their ages ranged between 18-45 years [mean = 31 years] and the number of previous losses ranged between 2-8 [mean = 4]. The clinical evaluation, pedigree construction, pelvic ultrasound examination was done to all cases. Chromosomal studies were done to 66 couples with history of early fetal losses [during 1st trimester] using GTG-banding technique. A total number of 120 pregnant women with history of fetal losses and 30 normal pregnant women used as controls was subjected to a further immunologic investigation. Anticardiolipin antibodies were measured using ELISA and lupus anticoagulant [LA] by activated partial thromboplastin time [APTT]. The study concluded that both genetic and immunologic factors have been identified as causes of repeated fetal losses. However, chromosomal aberrations play an important role in the etiology of early fetal losses