摘要:

AbstractMaternal age‐specific risks of giving birth to a child with the Down syndrome (DS) are given by single‐year age intervals. Such data are of value for more precise genetic counseling and in cost‐benefit analyses of prenatal diagnosis programs. The data were obtained by linking records of children with DS at the British Columbia Health Surveillance Registry (BCHSR) to the appropriate birth registrations to derive maternal ages. The data related to 519 affected children out of a total of 354,880 live births in British Columbia between 1961 and 1970. The results, which are based on a high level of ascertainment, are compared to those reported in the only other published study relating to risks by single‐year maternal age groupings, where completeness of ascertainment was estimated to be o

ISSN:0148-7299    

DOI:10.1002/ajmg.1320020102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1978

数据来源: WILEY

摘要:

AbstractA new test of goodness of fit for the polygenic threshold model is proposed. This test, when applied to disorders showing different incidence rates in males and females, is designed to account for ascertainment in more detail than previously done by other investigators. This is accomplished by computing the expected distribution of nuclear families with more than one affected sib conditioned on several family‐dependent variables, including whether each family was ascertained via only affeted boys or via at least one affected girl. A direct measure of the probability of observing a data set is thereby derived. The test, when applied to data on pyloric stenosis, exposes the critical nature of the ascertainment procedures. Different levels of statistical significance are obtained when mode of ascertainment is taken into account than when the mode of ascertainment is ignore

ISSN:0148-7299    

DOI:10.1002/ajmg.1320020103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1978

数据来源: WILEY

摘要:

AbstractA patien is shown to have acute granulocytic leukemia, bone marrow mosaicism, and cutaneous fibroblast mosaicism for trisomy 8, an inherited reciprocal translocation involving the short arms of chromosomes 7 and 20, and a family history of cancer. A normal sister who had the same balanced chromosome translocation was evaluated for a preleukemic state; the results were unremarkable. The inherited translocation and postzygotically derived trisomy 8 are thought to represent additive factors contributing to the development of leukemia in the patient.

ISSN:0148-7299    

DOI:10.1002/ajmg.1320020104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1978

数据来源: WILEY

摘要:

AbstractBone marrow fibroblasts were cultured from two patients with fucosidosis type 2, six control subjects, and three patients with other lysosomal disorders. Optimal conditions for measuring α‐L‐fucosidase activity in lysates of these cells with the fluorogenic substrate 4‐methylumbelliferyl‐α‐L‐fucoside were established. The pH profile of normal bone marrow fibroblasts showed three peaks and a shoulder of enzymatic activity, with maximum activity at pH 4.75. In cells derived from fucosidosis patients two peaks of apparent α‐L‐fucosidase activity were obtained; the pH optimum was 4.5. α‐L‐Fucosidase activity (mean ± SD) in the fucosidosis and control bone marrow fibroblasts was 2.5 and 312.4 ± 10.9 nmoles 4‐methylumbelliferone per milligram protein per hour, respectively. A reduction in the apparent specific enzymatic activity in the fucosidosis cells was observed by using increasing concentrations of cellular protein in the assay system. Mixing experiments between normal and fucosidosis cells gave the expected activities. These findings indicate that cultured bone marrow fibroblasts can be used for the diagnos

ISSN:0148-7299    

DOI:10.1002/ajmg.1320020105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1978

数据来源: WILEY

摘要:

AbstractThe variations and defects observed during detailed gross anatomical dissections of four cases of trisomy 13 are described. Emphasis is on the muscular system where previously undocumented variations, absences, and supernumerary elements were observed. A muscle phenotype which includes absence of palmaris longus, palmaris brevis, plantaris, and peroneus tertius, the presence of pectorodorsalis muscles and muscles from the central tendon of the diaphragm to the pericardium near the pulmonary veins, and variations in the extensor indicis, extensor carpi radialis longus and brevis, biceps, and suprahyoid muscles is discussed. The brain defects which include absent olfactory bulbs and tracts and hypoplastic commissures are compared to those defects seen in cases of alobar holoprosencephaly wherein severe defects of the ethmoid bone are concomitants. Previously well‐documented defects of the viscera are include

ISSN:0148-7299    

DOI:10.1002/ajmg.1320020106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1978

数据来源: WILEY

摘要:

AbstractThe advantages and disadvantages of evolutionary fitness (probability that a single mutant line will not become extinct) and genetic fitness (mean fecundity) are compared. For deterministic processes the two are equivalent, but for stochastic branching processes they may be totally unrelated except that an absolute genetic fitness of unity or less implies an evolutionary fitness of zero. To know the variance as well as the mean family size does not in general uniquely determine the evolutionary fitness.Except where genetic fitness is close to unity, the impact of selection is shown to be rapid for the binomial, Poisson, negative binomial, and truncated negative binomial distributions.Evolutionary fitness, though somewhat cumbersome, has greater relevance to evolution, genetic counseling, and voluntary population control; but genetic fitness which is much easier to handle is the more appropriate measure where a large number of mutants is involved.Some empirical data on the transmission of various types of characters from parent to child are analyzed to allow comparison of genetic fitness, Crow's index, and a Malthusian parameter, with evolutionary fitness. There is a fair, but far from perfect, agreement among them. Multiple correlation of evolutionary fitness with mean and variance of family size taken jointly suggests a much more satisfactory approximation. It thus appears that, at the least, the population geneticist cannot afford to ignore the variance (which is not adequately represented in Crow's index). These relationsips, based on two sets of data only may be accidental and should be invoked with caution. It seems more than likely that other aspects of the distribution of family size (eg, even higher moments) may contain relevant information in certain cases.

ISSN:0148-7299    

DOI:10.1002/ajmg.1320020107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1978

数据来源: WILEY

摘要:

AbstractWe report eight patients with the craniofacial defects and limb anomalies of the (amniotic deformity, adhesions, mutilations) ADAM complex. Facial abnormalities comprise clefts and distortion and dislocation of craniofacial structures; limbs show various combinations of amputation, secondary syndactyly, and constriction. From previous reports and our cases it is obvious that the clinical picture of the ADAM complex varies enormously; a less severe type combines cleft lip and palate with amputations or amniotic bands. Clinical and experimental data suggest that these malformations are of symptomatic (exogenous) origin. Nosologic differentation from other conditions phenotypically similar but of genetic etiology is important for genetic counseling. Observation of the ADAM complex in two members of a family suggests that genetic factors might operate in some cases.

ISSN:0148-7299    

DOI:10.1002/ajmg.1320020108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1978

数据来源: WILEY

ISSN:0148-7299    

DOI:10.1002/ajmg.1320020109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1978

数据来源: WILEY

ISSN:0148-7299    

DOI:10.1002/ajmg.1320020110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1978

数据来源: WILEY

ISSN:0148-7299    

DOI:10.1002/ajmg.1320020101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1978

数据来源: WILEY