ABSTRACT
Oligonucleotide probes have been used to map the myeloperoxidase (MPO) gene locus to chromosome bands 17q21-22. This is in agreement with results reported using conventional cDNA probes. No evidence for the existence of a second MPO gene locus was obtained. Six synthetic 72-base oligonucleotides, corresponding to different exon regions of the MPO gene, were tritium-labeled and used as in situ hybridization probes. Synthetic oligonucleotide probes offer a useful alternative to conventional DNA probes for gene mapping.
Subject(s)
Chromosomes, Human, Pair 17 , Peroxidase/genetics , Chromosome Banding , DNA Probes , Humans , Nucleic Acid HybridizationABSTRACT
This study was designed to test for the fragile X syndrome [fra(X)] in institutionalized male patients with nonspecific mental retardation, referral patients, and relatives of fra(X) patients. Thirty-one of 91 (34.0 per cent) subjects tested were positive for the fra(X) chromosome; relatives had the largest percentage of positives. The data reflect the value of this test for detecting families having potential carriers who can benefit from genetic counseling.
Subject(s)
Fragile X Syndrome/diagnosis , Sex Chromosome Aberrations/diagnosis , Female , Georgia , Humans , Institutionalization , Intellectual Disability/genetics , Male , RiskABSTRACT
Although prenatal genetic diagnosis can usually provide prospective parents with information as to whether their fetus is affected with certain genetic conditions, the presence of twins and the uncertainty about the phenotype of some chromosome variations pose a major dilemma and make genetic counseling very difficult. Here, a case report of an unusual chromosome aberration (pericentric inversion of chromosome no. 17) in a twin pregnancy which was originally suspected to be monoamniotic but later proved to have two sacs was presented.
Subject(s)
Chromosome Inversion , Pregnancy, Multiple , Prenatal Diagnosis , Twins , Adult , Amniocentesis , Chromosomes, Human, 16-18 , Female , Humans , Infant, Newborn , Male , PregnancySubject(s)
Amniotic Fluid/cytology , Cells, Cultured , Culture Media , Prenatal Diagnosis/methods , Female , Humans , PregnancyABSTRACT
Four families are described with a t(13q14q) segregating. Two of them were identified through index cases with Down's syndrome; their karotypes revealed the unusual 46,XY, -13, -14, +t(13q14q), +21. The other two families were identified through a chromosomal study of parents with repeated spontaneous abortions. Analysis of data on 3 of these 4 families and on 7 other from the published reports showed no evidence of increased fetal wastage among 13/14 carriers. However, the risk of producing offspring with various types of aneuploidy may be greater among carriers than among persons with a normal chromosome pattern. Qualitative and quantitative differences in D/D translocations may account for the observed variation in clinical findings. These differences add to the problem of determining genetic risks from an analysis of grouped data.