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The gene for epidermal growth factor receptor (EGFR) has been localized to the p14-p12 region of human chromosome 7 by somatic cell hybridization and radioisotope in situ hybridization techniques. In this paper, we report the precise mapping of the EGFR gene to the band p12 of chromosome 7 using a novel method in which fluorescence images from in situ hybridization and Q-banding are computer graphically merged. The novel procedure is described in detail. [ABSTRACT FROM AUTHOR]

Fluorescence in situ hybridization (FISH) with chromosome specific alpha-satellite DNA probes was used to estimate the rates of aneuploidy of chromosomes 1, 17, 18, X and Y in human ejaculated sperm. Sperm samples were collected from six donors, and biotinylated DNA probes, D1Z5, D17Z1, D18Z1, DXZ1 and DYZ3 were hybridized to interphase sperm which had been pretreated with dithiothreitol to expand their nuclei. A minimum of 3,000 sperm per donor were analyzed. The hybridization efficiency was 99.68% for all the five probes. The frequencies of aneuploidy for chromosomes 1, 17 and 18 were 0.65%, 0.66% and 0.61% respectively. For XX-and YY-sperm the frequencies were 0.28% and 0.27% respectively. To estimate the diploidy and disomy rates, a mixture of D17Z1 and D18Z1 were used as probes, and the frequency of diploid sperm was calculated to be 0.27%. After subtraction of the diploidy rate, the disomy rates for chromosomes 1, 17, and 18 were estimated to be 0.38%, 0.39% and 0.33%, respectively. The proportion of X- and Y-bearing sperm were 49.9% and 49.66%, consistent with an expected 1: 1 ratio. [ABSTRACT FROM AUTHOR]

The function of Sry for inducing a male gonad was identified due to a development of a transgenic XX male mouse with testes by introducing a single gene into an embryo. The intronless Sry encodes a putative transcriptional protein harboring an HMG motif. The sequence similarity within the HMG motif has been highly conserved despite less conservation in other domains. Hence, the HMG motif must play a critical role in the transcriptional regulation, leading to the development of a male gonad. However a non HMG box C terminal domain of Sry protein may also be indispensable for inducing normal testicular development. Further, serveral autosomal genes, such as SF1, WT1, SOX and MIS, as well as a unique X chromosomal DAX1 were suggested to be associated with the development of gonadal sex in mammals. Therefore, the significance on the involvement of these genes in the molecular mechanism of mammalian sex determination should be also considered. [ABSTRACT FROM AUTHOR]

Using the polymerase chain reaction method (PCR), we examined the allele frequencies and heterozygosities of 7 polymorphic sites (pERT87, and CA polymorphisms in the 5′ and 3′ regions) of the dystrophin gene in 20 Japanese Duchenne muscular dystrophy and Becker muscular dystrophy (DMD or BMD) families consisting of 36 males, including 23 cases of DMD and BMD, and 28 females. The allele frequencies of three primer and enzyme sets in the pERT87 locus were well comparable to those in the previously reported Japanese female cases but different from in other countries. The frequencies of 5′ markers of the dystrophin gene in Japanese were different from the reported Caucasian frequencies. As for 5′DYS-I and 5′DYS-II, the numbers of alleles in our cases were less than in Caucasians, and the heterozygosities of all three markers (5′DYS-I, II and III) were lower than in Caucasians. However, the 3′CA polymorphisms showed almost the same frequencies and heterozygosities as in Caucasians. All of our females showed a heterozygous pattern for at least one locus, with the combination of the seven markers. The usefulness of linkage analysis involving PCR methods with these intragenic, and 5′ and 3′ markers of the dystrophin gene in the carrier and prenatal diagnosis of DMD and BMD was confirmed by the successful prenatal diagnoses in 15 fetuses, the exception being one case considered to have a new mutation. [ABSTRACT FROM AUTHOR]

The gene responsible for Werner syndrome (WS) is considered to be located between D8S131 and D8S87 in the 8p11.2-12 region that includes the closest marker D8S339 (Goto et al. (1992) Nature 355: 735-738). In this experiment, the order of major markers in this region was determined and the physical distances between them were estimated by dual-color fluorescence in situ hybridization (FISH) using P1, PAC and cosmid clone DNAs as probes. The fine overall order of telomere-D8S131-D8S339-GSR-PP2Aβ-D8S283-D8S87-centromere was determined for the first time. The distance from D8S131 to D8S87 was estimated to be 1,634 kb. To our surprise, the distance between D8S131 and D8S87 is much shorter than previously estimated by recombination analysis, 8.3 cM equivalent to 8.3 Mb in physical distance. These information provide the basis for the positional cloning of WS gene and the identification of its mutation. [ABSTRACT FROM AUTHOR]

The allele frequency of a L1 retroposon insertion into intron 30 of the neurofibromatosis type 1 (NF1) gene was determined by analyzing amplified fragment lengths in seven Asian or Pacific populations; namely, Japanese, Chinese, Indian, Malay, Filipino, Indonesian and New Guinean. Nearly 100 chromosomes from each group were analyzed. The presence of the L1 insertion was identified by the appearance of an abnormally large PCR-amplified product. The insertion frequency varied from 0.45 to 0.75, depending on the population group. Malay and Indonesia populations were found to have the highest insertion frequencies (0.75 and 0.72, respectively), while the wild-type genotype was more prevalent in Indians. The lowest insertion frequency (0.45), observed in Indians, was nearest to that reported in Westerners (0.35). The different L1 insertion frequencies found in Asian and Pacific groups reflect a major divergence in these human populations. Japanese and Chinese populations showed the highest heterozygosity (0.50), suggesting the usefulness of this polymorphism in linkage analysis in these populations. [ABSTRACT FROM AUTHOR]

Myotonic dystrophy (DM) results from the expansion of an unstable CTG trinucleotide repeat in the 3′ untranslated region of mRNA encoding a putative serine/threonine protein kinase. The degreeoof the CTG repeat amplification in genomic DNAs extracted from lymphocytes correlates with disease severity. We have analyzed the amplification of the CTG repeat of DNAs extracted from skeletal muscles and lymphocytes in five congenital DM patients. The amplification from skeletal muscles showed an increase of about 1.5 kb to 3.5 kb larger than that from lymphocytes in all patients. Furthermore, we have investigated the somatic instability of the CTG repeat in various tissues from a severe congenital DM patient. [ABSTRACT FROM AUTHOR]

TBP (TATA box-binding protein) participates in the expression of eukaryotic genes transcribed by RNA polymerases I, II, and III. Molecular cloning of human TBP revealed that the N-terminal region contains a polymorphic (CAG) repeat. We report here the direct localization of human TBP gene to chromosome 6q2705→qter region by fluorescence in situ hybridization, using the cDNA clone with or without the (CAG) repeat as a probe. [ABSTRACT FROM AUTHOR]

Chymotrypsinogen is widely present in various animal pancreases. To study evolutionary relationship of chymotrypsinogen gene in species, we used a cDNA probe of human prechymotrypsinogen to investigate the species distribution of chymotrypsinogen gene, and designed oligodeoxynucleotide primers to investigate the genomic organization in the three domains of active sites. The genomic analyses showed that chymotrypsinogen gene is evolutionary conserved in species. On the basis of the deduced amino acid residues, a three-dimensional model for human chymotrypsinogen was further built by computer graphics. The model showed high similarity to the X-ray crystal structure of bovine chymotrypsinogen A, thus, demonstrated that the three-dimensional structure is more conserved in evolution than protein sequences. [ABSTRACT FROM AUTHOR]

Polymorphic N-acetyltransferase in human liver catalyzes N-acetylation of various arylamine-containing drugs and environmental chemicals. To accelerate the pharmacogenetic and ecogenetic studies of N-acetyltransferase polymorphism, we have developed a rapid and simple method for genotyping using a polymerase chain reaction based restriction fragment length polymorphism. This method distinguishes four kinds of allele of the N-acetyltransferase gene using a single polymerase chain reaction starting with a set of primers, followed by successive Asp718, BamHI and TaqI digestions, and then running the samples on a single electrophoresis lane. This method allows us to determine ten different genotypes easily and reliably. [ABSTRACT FROM AUTHOR]

A method of chromosome painting on human sperm chromosomes using fluorescent in situ hybridization (FISH) is introduced. Sperm chromosome slides were prepared after in vitro fertilization of hamster eggs with human spermatozoa. The slides were treated by RNase A before FISH. Chromosome 4 was clearly and specifically painted in a majority of sperm-derived metaphase plates after an application of whole chromosome painting DNA probes of this chromosome. This is the first report of successful painting on human sperm chromosomes. [ABSTRACT FROM AUTHOR]

Usually, the supernumerary isochromosome 12p characterizing Pallister-Killian syndrome patients was detected in cultured skin fibroblasts but not in cultured blood lymphocytes. The proband of this study was a one-day-old female, who presented with major clinical characteristics of the Pallister-Killian syndrome, and had severe malformations in the form of anal atresia, cleft palate, and severe laryngomalacia. Chromosome preparations from cultured blood lymphocytes and skin fibroblasts, as well as buccal smears, from this patient were analyzed by fluorescence in situ hybridization (FISH) using a chromosome 12-specific alpha satellite probe. The proportions of cells showing positive signals for i(12p) in these samples were found to be 20, 62.5, and 70% respectively. Repeated FISH studies of buccal smears from this patient showed considerable decreases in the proportions of i(12p) containing cells to 40% at one year of age and to 32% at the age of one year and five months. The decline in the percentage of i(12p)-containing cells in buccal smears with aging supports the concept of in vivo loss of the marker during repeated cell division. [ABSTRACT FROM AUTHOR]

We here report the molecular characterization of an Indonesian ovalocytosis. The analysis of genomic gene by polymerase chain reaction shows that the individual has two amplified products from a region encompassing exon 11 of the erythrocyte band 3 gene. The sequence of the larger product matched completely with that of normal individuals. In the sequence of the smaller product, 27 nucleotides within exon 11 disappeared. The deletion removes a total of nine amino acids in the boundary of cytoplasmic and membrane domains of band 3 protein, a membrane anion transporter protein. This is the first report to confirm the heterogeneous presence of an altered membrane band 3 protein in Indonesian ovalocytosis. [ABSTRACT FROM AUTHOR]

We have constructed a new genetic linkage map of the Werner syndrome (WRN) region, using microsatellites from a library which was developed by a chromosome microdissection and enzymatic amplification method. These microsatellites were used to genotype members of CEPH families using a simplified detection system of polymerase chain reaction (PCR) products. Two-point analysis was used to assign 4 microsatellite markers relative to each marker and other markers reported in the CEPH public data base. We confirmed that these 4 markers are located to the WRN region, 8p11.2-p22. Such microsatellites microdissected from the definite chromosome region may be useful for positional cloning. [ABSTRACT FROM AUTHOR]

A human chromosomal region, 15q11-q13, was microdissected, its DNA was amplified with the primer-linker PCR method, and the PCR products were cloned into a plasmid vector to construct a microclone library. Of 193 microclones analyzed with Southern blot hybridization on hybrid cell panels, 26 (13.5%) were either single-copy (unique) or low-repetitive fragments. By screening of a cosmid library of human genomic DNA using the 26 microclones as probes, 47 positive cosmids were obtained and underwent regional mapping with chromosome fluorescence in situ hybridization (FISH). Sixteen cosmids gave FISH signals at 15p-cen, 5 at 15q11-q13, 6 at 15q22-q26, 3 at other chromosomes, and 17 no signal. These 27 cosmids mapped to chromosome 15 are useful additions to the inventory of DNA markers of this chromosome including the much interested Prader-Willi/Angelman syndrome region. [ABSTRACT FROM AUTHOR]

Ethical issues in the clinical practice of fetal medicine are discussed, largely from the point of view of early prenatal medicine. The discussion concentrates on several aspects including the time when human life begins, the pros and cons of fetal medicine, and ethical guidelines for fetal medicine. The emphasis is placed on the importance of informed consent and an increase in genetical knowledge amongst the general public. [ABSTRACT FROM AUTHOR]

An alpha-antitrypsin deficiency associated with pulmonary emphysema was investigated in a 32-year-old Japanese male. Polymerase chain reaction (PCR)-amplified fragments and dot blot hybridization with allele-specific oligonucleotide probes revealed that the patient was homozygous for a C to T transition at codon 53, resulting in the substitution of Phe for Ser ( PI S). Crossedimmunoelectrophoresis after iso-electric focusing and agarose gel electrophoresis showed atypical banding patterns. PI S is a rare deficiency gene, but it can occur sporadically all over the Japan. [ABSTRACT FROM AUTHOR]

A population survey of a common folate-sensitive fragile site, fra(3)(p14.2), has been carried out on PHA-stimulated peripheral lymphocytes of patients with cancer and other diseases, under both culture conditions of folate deprivation and aphidicolin treatment. Overall findings regarding variability of expressivity due to age and sex were very similar to those obtained in a healthy population. The expression of fra(3)(p14.2) by folate deficient condition appeared hardly influenced by such exogenous factors as tobacco smoking habit, past histories of radiotherapy and chemotherapy, while it was associated with the unfavorable prognosis of cancers. Furthermore, proportion of those with higher expression was slightly but significantly larger in both lung and breast cancer patients. These findings suggest that some factors relevant to the expression of fra(3)(p14.2) may be associated with development and progression of certain kinds of cancer. [ABSTRACT FROM AUTHOR]