the 35delg mutation in the connexin 26 gene (cx26), at the dnfb1 locus is the most common mutation in the patients with autosomal recessive non-syndromic hearing loss (arnshl). we have studied a total of 224 deaf cases from 189 families in two populations of iran (sistan va bluchestan and hormozgan provinces) by prescreening nested pcr, polyacrylamide gel electrophoresis and consequent direct s...

a 39-year-old pregnant woman at 38 weeks of gestation was referred with labor pain to a hospital. she had consanguinity with her husband. a female newborn had multiple craniofacial anomalies and phocomelia in right upper limb. the disease locus was assigned to chromosome17q21. four days later, infant died of cardiopulmonary arrest.

congenital muscular dystrophy (cmd)  is an umbrella term collecting a heterogeneous groups of genetic disorders , mostly with autosomal recessive mode of inheritance , and are characterized by muscle weakness since birth or in early infancy , with a dystrophic pattern on muscle biopsy . these children are usually hypotonic and may have joint contractures . the serum creatine kinase level can be...

Karyotypes were examined in 512 (91.9%) of 557 male patients in an institution for the mentally handicapped. A total of 110 (21.5%) had an abnormal karyotype: 65 (12.7%) with Down's syndrome, 30 (5.9%) with the fragile X syndrome, 13 (2.5%) with autosomal anomalies other than Down's syndrome (12 unbalanced, one balanced), and two (0.4%) with sex chromosome anomalies.

Genomic imprinting results in preferential gene expression from paternally versus maternally inherited chromosomes. We used a genome-wide approach to uncover sex-specific parent-of-origin allelic effects in the adult mouse brain. Our study identified preferential selection of the maternally inherited X chromosome in glutamatergic neurons of the female cortex. Moreover, analysis of the cortex an...

In flies, scute (sc) works with its paralogs in the achaete-scute-complex (ASC) to direct neuronal development. However, in the family Drosophilidae, sc also acquired a role in the primary event of sex determination, X chromosome counting, by becoming an X chromosome signal element (XSE)-an evolutionary step shown here to have occurred after sc diverged from its closest paralog, achaete (ac). T...

A method is proposed to locate any new autosomal and recessive mutation in the Mediterranean fruit fly, Ceratitis capitata (Wied.). A series of crosses searches for pseudo-linkage between sex and the mutation by employing three strains with Y-linked translocations, thereby indicating its chromosome location.

Sex chromosome divergence, which follows the cessation of recombination and degeneration of the sex-limited chromosome, can cause a reduction in expression level for sex-linked genes in the heterozygous sex, unless some mechanisms of dosage compensation develops to counter the reduction in gene dose. Because large-scale perturbations in expression levels arising from changes in gene dose might ...

We describe 35 microsatellite markers from the human parasitic nematode Ascaris lumbricoides. We found 7 sex-linked markers and demonstrate that 26 autosomal loci can be scored reliably. These markers have high genetic variability and provide the tools to address multiple questions concerning the epidemiology, fine-scale genetic structure, host specificity, and mating systems of this parasite.