leukodystrophies are familial disorders with onset usually in infancy or childhood. the name comes from the greek leuko meaning white and dystrophy meaning imperfect growth or development. leukodystrophy is a progressive, genetic disorder with an autosomal recessive or x-linked mode of inheritance. the clinical features consist of motor dysfunction with varying degrees of cognitive decline. mag...

hemophilia b is factor ix deficiency and is inherited as x-linked recessive disorder. the subject of carrier detection in hemophilias has received new impetus in the last several years. analysis of factor ix gene polymorphisms is considered the best approach for prenatal diagnosis and hemophilia b carrier detection, if the identification of the gene mutation is possible. allele frequencies of t...

Congenital stationary night-blindness associated with myopia may be transmitted by two types of inheritance: X-linked recessive (Worth, 1906; Nettleship, 1909 and 1912; Kleiner, 1923) and autosomal recessive (Nettleship, 1912; Vogt, 1923; Gassler, 1925; Akiya, 1935; Merin et al, 1970). There are only a few reports of either variety. The present paper describes a family where 3 sibs are affected...

Dent’s disease 1 (OMIM 300009) is an X-linked proximal tubulopathy [1] first described in 1964 [2], with Fanconi syndrome, a consistent renal abnormality, and low-molecular-weight proteinuria (LMWP) being almost always present. Nephrocalcinosis and renal stone formation occur more frequently in Dent’s disease 1 than in other forms of Fanconi syndrome. Various features of Dent’s disease 1 predom...

GENETIC DISORDERS ARE TRADITIONALLY CATEGORIZED INTO THREE MAIN GROUPS: single-gene, chromosomal, and multifactorial disorders. Single gene or Mendelian disorders result from errors in DNA sequence of a gene and include autosomal dominant (AD), autosomal recessive (AR), X-linked recessive (XR), X-linked dominant and Y-linked (holandric) disorders. Chromosomal disorders are due to chromosomal ab...

Twenty-two of 23 obligate female carriers in nine families with known X-chromosome-linked retinitis pigmentosa were detected on the basis of abnormal full-field electroretinograms (ERGs). Only 14 of these carriers had fundus findings characteristic of the carrier state. Electroretinograms of carriers were either reduced in amplitude to white light under dark-adapted conditions or delayed in con...