X-linked recessive myotubular myopathy (XLMTM) is a severe congenital muscle disorder caused by mutations in the MTM1 gene and characterized by severe hypotonia and generalized muscle weakness in affected males. It is generally a fatal disorder during the neonatal period and early infancy. The diagnosis is based on typical histopathological findings on muscle biopsy, combined with suggestive cl...

Sex linked dystonia parkinsonism (XDP), also referred to as “lubag” in American literature, was described in 1975 occurring endemically in Panay, Philippines. It is an adult onset, sex linked, predominantly male, severe, progressive movement disorder with high penetrance and a high frequency of generalisation. The movement disorder is characterised by dystonic movements, usually starting in the...

Adrenoleukodystrophy (ALD) is a rare X-linked inherited leukodystrophy with a reduced capacity for degradation of very long chain fatty acids (VLCFAs). The intracellular accumulation of VLCFA leads to demyelination in the central nervous system (CNS) and cell destruction in the adrenal glands. ALD primarily affects males; however, females may develop milder symptoms that may be difficult to rec...

We mapped a new X-linked recessive atrophic macular degeneration locus to Xp21.1-p11.4 and show allelic involvement of the gene RPGR, which normally causes severe peripheral retinal degeneration leading to global blindness. Ten affected males whom we examined had primarily macular atrophy causing progressive loss of visual acuity with minimal peripheral visual impairment. One additional male sh...

A 2-year-old boy with psychomotor retardation, congenital unilateral ptosis, bilateral adducted thumbs, weakness of upper limbs, and Hirschsprung's disease (aganglionosis), with complete agenesis of the corpus callosum and hypoplasia of the inferior vermis and cerebellum is reported. His 24-year-old maternal uncle, with severe psychomotor retardation but none of the other physical problems, als...

Two families are described in which the Ehlers-Danlos syndrome is apparently transmitted as an X-linked recessive character. The results of tests for the Xg blood groups and for colour vision show that the locus for the Ehlers-Danlos syndrome is not close to that for the Xg groups nor very close to the locus for deutan colour-blindness.The clinical features of this variety of the Ehlers-Danlos ...

Recessive deleterious mutations are common, causing many genetic disorders in humans and producing inbreeding depression in the majority of sexually reproducing diploids. The abundance of recessive deleterious mutations in natural populations suggests they are likely to be present on a chromosome when a new adaptive mutation occurs, yet the dynamics of recessive deleterious hitchhikers and thei...