The myotonic dystrophy (DM) gene is localized to the proximal long arm of chromosome 19. There have been reports of tight linkage to a number of chromosome 19 markers, including APOC2 and creatine kinase muscle type (CKMM), but they did not establish orientation of the 2 markers to DM. We screened several large multi-generational DM families for linkage to a series of chromosome 19 markers including CKMM.
View Article and Find Full Text PDFCytogenet Cell Genet
April 1991
Cystic fibrosis is the commonest autosomal recessive genetic disorder among northern Europeans and their descendants. Recently, investigators have mapped the gene for cystic fibrosis to chromosome 7. We report the results of DNA linkage analysis in a consanguineous family with mild cystic fibrosis.
View Article and Find Full Text PDFBy using the genetic linkage data between the facioscapulohumeral muscular dystrophy (FSHD) gene and 57 markers on various autosomes, we have constructed an exclusion map for this disorder. The maximum likelihood location of the FSHD gene and the percentage of the excluded areas on each chromosome are presented here. This exclusion map shows that more than 80% of the genome has been excluded as a likely location of any locus responsible for FSHD in the majority of families.
View Article and Find Full Text PDFFacioscapulohumeral disease is probably a heterogeneous disorder. We have ascertained and sampled two multigeneration families with the neurogenic form of this disorder, considered to be a type of spinal muscular atrophy (FSHSMA). The two families have 36 affected members.
View Article and Find Full Text PDFFamilial amyotrophic lateral sclerosis (FALS) constitutes 5 to 10% of cases of ALS and, in most families, its inheritance is consistent with an autosomal dominant trait with age-dependent penetrance. The biochemical abnormality underlying the disorder is unknown. We analyzed DNA from 131 members of 6 multigenerational ALS families, which included 13 affected members, for genetic linkage to 39 expressed and DNA markers, using the techniques of 2-point linkage analysis, multilocus linkage analysis, and exclusion mapping.
View Article and Find Full Text PDFDNA isolated from a family segregating a deletion in the Duchenne muscular dystrophy gene and control families was digested with restriction enzymes, Southern transferred, and probed with a radioactive dystrophin cDNA probe. The resulting autoradiographs were analyzed with a densitometric spectrophotometer to detect carriers of the deletion. The carrier status of females in the deletion pedigree was independently determined by genomic probes and confirmed by densitometry.
View Article and Find Full Text PDFA mutation leading to tuberous sclerosis was linked to the ABO blood group locus (9q34) on the long arm of chromosome 9. In an effort to confirm this assignment, nine multigenerational families with tuberous sclerosis, comprising 126 sampled individuals, were assessed for linkage of the ABO locus to tuberous sclerosis. Two-point linkage analysis and multilocus linkage analysis were used to evaluate linkage between tuberous sclerosis and the markers ABO, MCT136, and AblK2.
View Article and Find Full Text PDFCharcot-Marie-Tooth disease Type 1 (CMT) is an inherited neuropathy with known genetic heterogeneity, with at least one autosomal dominant form (CMT Type 1b) linked to the Duffy region of chromosome 1. Autosomal dominant families not demonstrating linkage to the Duffy blood group marker have been designated CMT Type 1a. We report linkage of six CMT Type 1a families to the chromosome 17 markers EW301 (D17S58) and pA10-41 (D17S71) with maximum LOD scores of zeta = 10.
View Article and Find Full Text PDFCytogenet Cell Genet
November 1989
The von Recklinghausen neurofibromatosis (NF1) gene has been mapped to the pericentromeric region of chromosome 17. We conducted linkage analyses of NF1 by using 10 polymorphic DNA markers from this chromosomal region. We ascertained 20 American Caucasian NF1 families (163 individuals, 98 NF1 affected) in Michigan and Ohio and also studied a large family ascertained primarily in North Carolina.
View Article and Find Full Text PDFThe defective gene causing von Recklinghausen neurofibromatosis (NF1), one of the most common inherited disorders affecting the human nervous system, was recently mapped to chromosome 17. We have used additional DNA markers to further narrow and bracket the NF1 defect. A multipoint linkage analysis suggests that the NF1 gene is flanked by D17Z1 on the centromeric side and by EW 207 on the telomeric side of the long arm of chromosome 17.
View Article and Find Full Text PDFThe von Recklinghausen neurofibromatosis (NF1) gene has been localized to the pericentromeric region of chromosome 17. We have screened six multigenerational families with multiple, tightly linked markers to aid in mapping this region of the chromosome. More than 150 members in six families were typed with probes including HHH202, D17Z1, EW203, EW206, EW207, EW301, pA10-41, D17S37, and D17S36.
View Article and Find Full Text PDFAlzheimer's disease is a devastating neurological disorder and the leading cause of dementia among the elderly. Recent studies have localized the gene for familial Alzheimer's disease to chromosome 21 in a series of early onset AD families (mean age of onset less than 60). Familial late onset AD (mean age of onset greater than 60) is a more common clinical form of the disorder.
View Article and Find Full Text PDFAccurate carrier testing and prenatal diagnosis in Duchenne muscular dystrophy (DMD) families is facilitated when an Xp21 deletion is found to be segregating within a family. We discuss the results of the DNA testing in two families, one in which DNA from affected males was available for study and the other in which no DNA from an affected male was available. Factors complicating the counselling of DMD deletion families are outlined.
View Article and Find Full Text PDFLimb-girdle muscular dystrophy is a syndrome of progressive myopathic weakness affecting shoulder and hip girdle and proximal arm and leg muscles. The disease occurs either sporadically or inherited as an autosomal recessive trait. Autosomal dominant inheritance is rare.
View Article and Find Full Text PDFDNA probes are available for Duchenne muscular dystrophy (DMD) carrier detection and prenatal diagnosis. With probes for about 25% of the proximal portion of the gene, we found the proximal probes detected deletions in 23% of nonselected DMD boys, while a single distal probe detected 17% more as deletions. The combined percentage was 39% for all probes tested.
View Article and Find Full Text PDFCytogenet Cell Genet
February 1989
Three separate lines of evidence led to the assignment of the Duchenne muscular dystrophy (DMD) gene to the 21.2 band on the short arm of the X chromosome. A portion of the putative gene, thought to extend over 1-2 million base pairs has been recently cloned.
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