摘要:

A genetic analysis of twins at school was undertaken using as variables urinary concentrations of kallikrein, catecholamines, sodium and potassium which have been demonstrated to be associated with blood pressure levels. In addition to these variables, urinary concentrations of urea nitrogen and inorganic sulfate sulfur which are indices of protein intake were investigated. 35 pairs of monozygotic twins and 19 pairs of dizygotic twins aged from 6 to 14 years were examined. Variance and correlation tests for genetic analysis indicated that in school children, hereditary factors play a role in the control of urinary potassium, sodium and kallikrein excretion. However, with regard to the urinary excretion of catecholamines, urea nitrogen and inorganic sulfate sulfur, hereditary control is not so apparent.

ISSN:0001-5652    

DOI:10.1159/000154317

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

A rotating optokinetic drum was used in three laboratory studies to test the hypothesis that Asian subjects are hypersusceptible to motion sickness. The results of the first study showed that Chinese women compared to European-American and African-American women experienced significantly more severe symptoms of motion sickness and greater disturbance of normal gastric myoelectric activity. A second study yielded similar results using American-born children of Asian parents. The results of a third study using Chinese men and women were similar and showed a significant increase in vasopressin during rotation. Possible genetic mechanisms that may account for these results are discussed.

ISSN:0001-5652    

DOI:10.1159/000154318

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The α-thalassemia mutations in 34 Jewish patients of various origins and in 13 Arab patients have been identified using DNA technologies. Middle Eastern Jews and Arabs have both deletional and nondeletional mutations, but in the former the most frequent mutation is the Mediterranean deletion while in Arabs it is the polyadenylation signal mutation. Another nondeletional mutation, the 5 bp deletion at the IVS1 splice donor site has only been found in Arabs. Yemenite and European Jews have only deletional mutations and the most frequent is the 3.7 kb deletion. A long deletion that involves the two α-globin genes, is found only in Yemeni

ISSN:0001-5652    

DOI:10.1159/000154319

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Both single-entry two-step (SETS) couple screening and double-entry two-step (DETS) couple screening have been recommended as methods to screen for cystic fibrosis gene carriers. In this paper we compare the expected results from both types of screening. In general, DETS results in a higher detection rate of couples in which both partners are carriers, but also in a higher proportion of couples with only one identified carrier who have a significant remaining risk in their offspring.

ISSN:0001-5652    

DOI:10.1159/000154320

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Ten individuals registered at the Danish Cholinesterase Research Unit were examined at the DNA level for the presence of the K allele of plasma cholinesterase, using amplification-created restriction sites (ACRSs). A further nine members of a family registered at the unit were tested for mutations of the K and atypical variants. The frequency of the K allele was calculated from examination of normal material from 25 individuals, representing 50 random alleles. The results show that the ACRS method successfully demonstrates the presence of the K variant, whose frequency in the Danish population was found to be 0.18. We conclude that this technique is a reliable and rapid non-radioactive diagnostic assay for detecting the plasma cholinesterase K variant.

ISSN:0001-5652    

DOI:10.1159/000154321

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

This study comprised 544 nuclear families with 2,925 individuals tested for the Mitsuda reaction, from the Campinas region in Brazil. Segregation analyses suggest the segregation of a major gene (χ21 – 0.07 – 0.07 = 0, p = 1), by failing to reject the hypothesis of Mendelian transmission and by rejecting the hypothesis of nontransmission of a major gene (χ23 0.99; χ22 = 198.28 – 0.0 = 198.28, p

ISSN:0001-5652    

DOI:10.1159/000154322

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The investigation of a DNA-amplified fragment of a phenylketonuria (PKU) patient by sequencing reveals a novel mutation in the PAH gene. This mutation represents the deletion of a single base (guanine) localized at the intron 11/exon 12 junction. This newly described mutation may be a frameshift or a splicing mutation. The identified mutation expresses phenotypically as the severe form of PKU.

ISSN:0001-5652    

DOI:10.1159/000154323

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Three different p53 DNA polymorphisms (a 16-bp duplication in intron 3 and BstUland MsplRFLPs in exon 4 and intron 6, respectively) and haplotype combinations were studied in some major ethnic groups: Caucasians (Swedes), Chinese, Dravidian Indians and African Blacks. Significant ethnic differences in single polymorphisms were found between all groups except for African Blacks-Dravidian Indians, who differed only in their MspI7-16-bp duplication haplotype distribution. Since previous results have shown that p53 alleles are correlated with latitude (degree of insolation), the similarity between these two groups, who are genetically quite distinct, may be due to ecological adaptation to similar climatic conditions. All other major ethnic groups differed significantly from each other with respect to their haplotype distributions; thus, p53 alleles and haplotypes should be very useful as anthropological markers. Asiatic Mongoloid groups appear to be characterized by very low frequencies of the 16-bp duplication and the MspIA1 allele. These mutations have probably been introduced by migration to east Asia from either Europe or Africa, where the highest frequencies were found. The results of this study indicate that p53, besides its role as a tumor suppressor, shows distinct ethnic heterogeneity and may be involved in ecological (climatic) adaptation.

ISSN:0001-5652    

DOI:10.1159/000154324

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Three p53 DNA polymorphisms (BstUIand MspIRFLPs in exon 4 and intron 6, respectively, and a 16-bp duplication in intron 3) and their haplotype combinations were studied in 73 patients (61 males and 12 females) with nasopharyngeal cancer and 105 healthy controls from the Guizhou province in southern China. Increased frequencies of the 16-bp A2 allele (p = 0.005), MspIAl allele (p = 0.021) and the BstUlAl (Pro) allele (p = 0.072) were found among the patients, with more pronounced differences in male patients (p = 0.003,0.014 and 0.052, respectively). Haplotype frequencies and linkage dis-equilibria differed from those in Caucasians. The differences between controls and patients, especially male patients, increased when the analysis was based on haplotypes. The lowest risk for nasopharyngeal cancer was associated with the haplotype 16-bp Al, BstUIA2, MspIA2 (1-2-2). A somewhat higher risk was observed in the 1-1-2 haplotype (replacing the Arg with a Pro allele). The highest risk was, however, found in the rare combinations including the 16-bp A2 and MspIAl alleles with an odds ratio of 4.9 [95% confidence interval (CI) = 1.8-13.2] in all patients and 5.4 (95% CI = 2.0-14.8) in male patients. The haplotype associations found in this study differ from those found in previous cancer association studies in Caucasians. This together with the fact that the intronic markers conferred the highest risk figures suggest that the mechanism behind the observed associations is linkage disequilibrium and not direct functional involvement of the codon 72 alleles.

ISSN:0001-5652    

DOI:10.1159/000154325

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

For a phase-unknown nuclear family, we show that the likelihood and lod score are unimodal, and we describe conditions under which the maximum occurs at recombination fraction θ = 0, θ = ½, and 0 < θ < ½. These simply stated necessary and sufficient conditions seem to have escaped the notice of previous statistical geneticist

ISSN:0001-5652    

DOI:10.1159/000154326

出版商:S. Karger AG    

年代:1996

数据来源: Karger