摘要:

Reciprocal translocations were studied in two groups of balanced carrier couples: 202 had 210 translocation aneuploid liveborn (LB) infants, and 95 couples had repetitive abortions (AB) without liveborn ancuploids. The observed translocation aneuploidies in the LB group were compared to predicted potential aneuploidies in A B by frequency of chromosome involvement, meiotic segregation mode, and mean trisomic, monosomic and combined genomic imbalances. Qualitative and quantitative differences identified genomic regions and chromosomes possibly vital forin uterosurvivability. LB aneuploidies indicate non‐random chromosome involvement, selection of least detrimental segregants and segments, and predominant transmission from maternal balanced carriers (especially in 3:1 tertiary segregation, 93.5%). For an individual with a balanced reciprocal translocation and untested reproductive capability, an approach is given for predicting whether a translocation aneuploid conceptus will be liveborn or aborte

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1985.tb00179.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Sphingomyelinase activities were assayedin vitroin cultured skin fibroblasts of 61 patients with Niemann‐Pick disease (NPD). Residual activities found in type A and B were 1% and 4%, respectively, of the mean control values, i.e. significantly higher in type B. In 27 cases with NPD type C, the mean activity was 42% of that in controls, with residual activities ranging from 15% up to normal. Fifteen pregnancies at risk for NPD type A and B were monitored; 4 affected foetuses were found.The uptake of exogeneously added radiolabeled sphingomyelin by cultured cells and metabolism of the choline moiety of this lipid were studied in 35 patients with NPD and 14 controls. No difference of uptake between normal and mutant cells was observed. Normally, 77 ± 5% of the radioactivity taken up was converted to phosphatidylcholine after 18 h incubation, compared to 5±2% (n = 7) in NPD type A. A substantially greater hydrolysis (31 ±12%; n = 8) occurred in NPD type B, and the test allowed complete discrimination between these two types. In NPD type C, 16 patients showed an abnormally low rate of intracellular sphingomyelin degradation (48 ± 5%) while 4 others were not distinguishable from controls. There was a correlation (r = 0.76) between the results of thein vitroandin vivoassays, but also between the severity of the clinical symptoms and the impairment in sphingomyelin degradation. For the diagnosis of NPD type C, thein vivotest gave more reproducible and more clearcut results than thein vitro

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1985.tb00180.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

In the present investigation we directly studied the constancy of the relative risks for standard 21 trisomy in Belgium during the period 1960–1978.The relative risk for standard 21 trisomy in different maternal age‐groups, as compared to 20–24 years and 40–44 years remained remarkably constant during the period under investigation. The increasing percentage of children with standard 21 trisomy born to younger mothers does not result from an increased risk for mothers of this maternal age‐group, but results from the general shift towards a younger maternal age at birth for the total population of births i

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1985.tb00181.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

In a study on the HLA‐DR antigens and phenotypes in a series of Dutch coeliac children and their first‐degree relatives, the B‐cell antigens of 36 unrelated coeliac children, 110 first‐degree relatives of 33 of them, and 201 controls were typed with the two‐colour fluorescence test. The most frequent antigen was HLA‐DR3 (69%), followed by DR7 (36%). The distribution of DR phenotypes showed that the most frequent was DR3/other DR (25%), followed by DR3/DR7 (17%), DR3/DR4 (14%), and DR3/DR3 (14%). However, due to the frequency of certain antigens in the controls, only phenotypes DR3/DR3 (relative risk = 6.2), DR3/DR7 (relative risk = 6.4), and DR3/DR4 (relative risk = 6.2) were significantly associated with CD. The family study confirmed the segregation of the disease with phenotypes DR3/DR3 and DR3/DR7. The present results show that the association between CD and phenotypes DR3/DR3 and DR3/DR7 is not an exclusive characteristic of Southern coeli

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1985.tb00182.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Fibroblast cell strains were obtained from skin biopsies taken from patients with adenomatosis of the colon and rectum (ACR), and their relatives. A total of 50 different fibroblast strains were tested for their frequencies of sister chromatid exchange (SCE) in vitro. These strains included nine from patients with the Gardner syndrome, 21 from patients with non‐Gardner ACR, and 20 cell strains from healthy relatives who were not at an increased risk for ACR. In 23 strains, the SCE frequencies after in vitro exposure to N‐methyl‐N'‐nitro‐N‐nitroso‐guanidine (MNNG) were also determined. Both with and without MNNG induction, SCE values in the Gardner strains were found to be significantly higher than in the control strains (p<0.02 and p<0.03, respectively). Non‐Gardner ACR strains differed only slightly from controls, thus making the difference between the control group and the pooled Gardner + non‐Gardner ACR group not significant. In all groups, there was a significant increase in SCE after MNNG exposure, and those strains which had low SCE values spontaneously, also tended to have relatively moderate SCE values after MNNG induction. There was no significant difference between the ratios of SCE values with and without MNNG exposure in the

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1985.tb00183.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Clinical management of neonates with Trisomy 18 depends on a knowledge of life expectancy. True estimates of potential life span are required for genetic counselling purposes when parents interpret the genetic threat, not only in terms of the mathematical odds involved, but also in terms of the quality and length of life of an affected infant, should such be born. This paper reports the findings from a study to generate life tables for Trisomy 18. This study is a total population study over 10 years based on a primary population of 2.2 million. Forty‐eight cases of Trisomy 18 were identified, five at amniocentesis. Four of the 43 clinical cases (9%) were mosaics. The median life expectancy for live‐born infants was five days (range one hour to 18 months). Mean age at death was 48 days. Life tables, by sex and by sub‐types (associated congenital abnormalities) are presented. The annual incidence is 14 per 100,000 total births, with a prevalence estimate of 0.06 per 100,000 total popul

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1985.tb00184.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

There have been conflicting reports that individuals with Huntington disease (HD) are prone to abnormalities of carbohydrate metabolism. In this study information about the incidence and control of diabetes mellitus in 620 probands (278 living, 332 deceased) with HD and in their first and second degree relatives was obtained by questionnaire method from participants of the National HD Research Roster. Among the probands, 65 individuals (10.5%) were identified by the informant or verified by examination of Roster family records as diabetic. The prevalence of diabetes, particularly among those less than 50 years of age, is significantly greater than corresponding figures among the general U.S. Caucasian population (Scott 1977, Krolewski&Warram 1985). Incidence rates were not calculated because of ascertainment and other biases in the data. Results from the analysis of family data indicate that HD affected relatives of an HD proband with diabetes are 7 times as likely to have diabetes over the proband's non‐HD relatives. A non‐diabetic HD proband is equally likely to have an HD or non‐HD relative with dia

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1985.tb00185.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

The first appearance of an autosomal dominant disease in a family is often attributed to new mutation, and the parents may be given a very low risk of recurrence for future offspring. This counseling is not appropriate if penetrance of the disease is incomplete and the reproductive fitness of affected individuals is close to normal. The risk of recurrence (PR) for an autosomal dominant disease in the sibling of an affected child, neither of whose parents is affected, may be estimated as:PR= y(1‐y)/2(2‐y‐f)where f is fitness of the carrier genotype regardless of phenotype, y is penetrance, and mutation‐selection equilibrium is assumed to exist. Recurrence risks have been calculated with this formula for various values of f and y. In cases in which penetrance is moderate and fitness is moderate or high, the risk of recurrence in siblings of the proband is often greater than 10%. When fitness is very high (f±0.9), the risk to siblings may be greater than 25%. These observations have important implications for genetic counseling and may also affect mutation rate calculations, demonstration of paternal age effects, and determination of inheritance patterns in genetically heterogeneous co

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1985.tb00186.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

A 46,XX,t(1;21)(q12;q22) carrier was ascertained because of two abortions. The non‐reciprocal nature of the rearrangement was demonstrated in 5‐azacytidine treated preparations with highly decondensed and somatically paired heterochromatic regi

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1985.tb00187.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

A non‐Jewish child with late onset GM2gangliosidosis is described. Tissues from the patient had near normal hexosaminidase A (hex A) activity using 4‐methylumbelliferyl‐2‐acetamido‐2‐deoxy‐β‐D‐glucopyranoside (MU‐glcNAc) as substrate, and deficient activity when assayed with the 6‐sulfate derivative of MU‐glcNAc (MU‐glcNAcS) or GM2in the presence of activator. We present evidence that this patient is a genetic compound for different oc‐subunit mutations. The father's tissues have hex A activity in the heterozygote range when assayed with MU‐glcNAcS, but normal activity using MU‐glcNAc; the mother's tissues have activities toward both substrates in the heterozygote range. These results emphasize the pitfalls of using only MU‐glcNAc for the diagnosis of unu

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1985.tb00188.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY