Biomaterial Database

Linkage studies in a family with X-linked recessive ichthyosis employing a cloned DNA sequence from the distal short arm of the X chromosome. 1983

P Wieacker, and K E Davies, and B Mevorah, and H H Ropers

Recently linkage has been described between the Duchenne muscular dystrophy (DMD) gene and a cloned DNA sequence, RC8, that detects restriction fragment length polymorphism and is derived from the distal short arm of the X chromosome. Positive lod scores between RC8 and Xg prompted us to examine the linkage relationship of RC8 to the steroid sulfatase-X-linked recessive ichthyosis (XRI) locus which is situated 15 cM proximal from Xg in the subtelomeric region of Xp. Unexpectedly, at least two crossovers were found among nine informative meioses of an informative family, suggesting that RC8 and XRI may be about 25 cM apart. This implies that the genetic distance between the Xg locus and the DMD locus may exceed 50 cM.

UI	MeSH Term	Description	Entries
D007057	Ichthyosis	Any of several generalized skin disorders characterized by dryness, roughness, and scaliness, due to hypertrophy of the stratum corneum epidermis. Most are genetic, but some are acquired, developing in association with other systemic disease or genetic syndrome.	Xeroderma,Ichthyoses,Xerodermas
D008040	Genetic Linkage	The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.	Genetic Linkage Analysis,Linkage, Genetic,Analyses, Genetic Linkage,Analysis, Genetic Linkage,Genetic Linkage Analyses,Linkage Analyses, Genetic,Linkage Analysis, Genetic
D008297	Male		Males
D010375	Pedigree	The record of descent or ancestry, particularly of a particular condition or trait, indicating individual family members, their relationships, and their status with respect to the trait or condition.	Family Tree,Genealogical Tree,Genealogic Tree,Genetic Identity,Identity, Genetic,Family Trees,Genealogic Trees,Genealogical Trees,Genetic Identities,Identities, Genetic,Tree, Family,Tree, Genealogic,Tree, Genealogical,Trees, Family,Trees, Genealogic,Trees, Genealogical
D011110	Polymorphism, Genetic	The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.	Gene Polymorphism,Genetic Polymorphism,Polymorphism (Genetics),Genetic Polymorphisms,Gene Polymorphisms,Polymorphism, Gene,Polymorphisms (Genetics),Polymorphisms, Gene,Polymorphisms, Genetic
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004262	DNA Restriction Enzymes	Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.	Restriction Endonucleases,DNA Restriction Enzyme,Restriction Endonuclease,Endonuclease, Restriction,Endonucleases, Restriction,Enzymes, DNA Restriction,Restriction Enzyme, DNA,Restriction Enzymes, DNA
D005260	Female		Females
D005808	Genes, Recessive	Genes that influence the PHENOTYPE only in the homozygous state.	Conditions, Recessive Genetic,Genetic Conditions, Recessive,Recessive Genetic Conditions,Condition, Recessive Genetic,Gene, Recessive,Genetic Condition, Recessive,Recessive Gene,Recessive Genes,Recessive Genetic Condition