摘要:

Reliable risk figures are available for regular trisomy G cases and the more common translocation types. In trisomic Down’s syndrome risk figures depend on maternal age. In the maternal age group below 30 the available materials lead to an estimated risk of recurrence of 1–2%. In translocation cases the risk depends on the type of translocation and the sex of the carrier. In (DqGq) translocations, risk figures of about 10% have been estimated for female carriers. Nearly the same risk was obtained for females with (21q22q) translocation. For male carriers the risk could not be estimated separately, but it is considered to be small (at most a few per cent). More research is needed concerning the role which chromosomal variation and other chromosomal abnormalities may play in the origin of Down’s syn

ISSN:0001-5652    

DOI:10.1159/000152346

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

A statistical segregation analysis of seven families with inherited (21q22q)-tranlocations is carried out. The risk figure for Down’s syndrome in the offspring of female carriers is estimated to be 8.9%. The corresponding figure for the offspring of male carriers is not found to be significantly smaller than that for female carriers, but it cannot be estimated separately since the only patients with carrier fathers are probands. These results may be changed in future when a larger material is available. From the whole material the risk figure for Down’s syndrome is estimated to be 4.1%. The risk for a phenotypically normal child to be a carrier is estimated to be 53.0%. This value does not depend on the sex of the carrier par

ISSN:0001-5652    

DOI:10.1159/000152347

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Methods are outlined for incorporating information from genetical linkage in the prediction of genotypes, for discrimination of genetic entities, for advice to adults, and for antenatal diagnosis. Current limitations to the usefulness of these methods are discussed.

ISSN:0001-5652    

DOI:10.1159/000152348

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Data on 168 families from West Bengal, India, are analysed to test the following three theories for the inheritance of hypertrichosis of the ear rims: (1) Y-linkage, (2) autosomal dominance and (3) autosomal recessivity. The present data support the Y-linkage theory only. Most of the methods used are found in Slatis and Apelbaum [7], though some of them are modified here. Also, some association studies are carried out between age, hypertrichosis, chest hair and head baldness.

ISSN:0001-5652    

DOI:10.1159/000152349

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

The frequency of finger and palmar dermatoglyphic patterns was studied in 239 patients with familial deafness, their 155 unaffected parents and siblings and 456 hearing school-children. Differences between the deaf patients and controls, as previously reported, were not confirmed. The frequency of simian crease, including transitional forms, according to ethnic group (Arabs, Sephardi and Ashkenazi Jews) among 979 hearing school-children showed significant differences according to sex and ethnic group. Considering the sex and ethnic group differences, the deaf patients showed the highest frequency of bilateral transitional forms, while their unaffected parents and siblings showed the highest frequency of unilateral transitional forms of simian crease. The diagnostic value of these findings is discussed.

ISSN:0001-5652    

DOI:10.1159/000152350

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Susceptibiliy to motion sickness and to frost-bite in three year old children and in their parents has been investigated by means of interviews with one or both parents and by mailed questionnaires to the paternal and maternal grandmothers. (1) Parents who had suffered from motion sickness in their childhood had significantly more susceptible children. The incidence of susceptible children was highest in matings where both parents had presented symptoms of this disorder. The same applied to frost-bite. (2) At the age of 3 years girls suffered more frequently (12.1%) from motion sickness than boys (6.5%). Females were found to be more prone to motion sickness than males in childhood as well as later in life. (3) Up to the age of 3 years symptoms of frost-bite had been observed with nearly the same frequency (6–7%) in girls and in boys. About ⅓ of adults were found to have suffered from frost-bite during childhood and/or later in life. (4) The observations did not support the assumption of simple Mendelian dominant or recessive inheritance, autosomal or sex-linked, but favoured polygenic inheritance of susceptibility to these condition

ISSN:0001-5652    

DOI:10.1159/000152352

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

The frequency data available at present on populations throughout the world for the isozyme variants of the enzyme adenylate kinase are tabulated and the frequencies of the AK2 gene are plotted on a world map. The significance of the distribution pattern of the AK2 gene is discussed.

ISSN:0001-5652    

DOI:10.1159/000152353

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

For the enzyme 6-phosphogluconate dehydrogenase, a table is given of all available data on the distribution of isozyme phenotypes. The calculated frequencies of all but the commonest gene are also tabulated. The frequencies of the PGDC allele are plotted on a world map. Possible interpretations of the observations are discussed.

ISSN:0001-5652    

DOI:10.1159/000152354

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

The relation between the pregnancy zone (Smithies) and a series of genetic and perinatal factors was studied in 406 deliveries. The detectability of the pregnancy zone was strongly influenced by the haptoglobin type. The pregnancy zone was found in a significantly higher frequency among mothers carrying a fetus of female sex. The pregnancy zone protein showed no relation to other perinatal factors such as maternal age, parity, abortion history and maturity criteria.

ISSN:0001-5652    

DOI:10.1159/000152355

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

An assay of G-6-PD activity was undertaken in a sample of 54 Brazilian Caucasoid twin pairs (14 MZ♂♂, 17 DZ ♂♂, 13 MZ ♀♀ and 10 DZ ♀♀) randomly collected. The data presented do not support either the hypothesis of genetic control of G-6-PD activity by isoalleles or other unknown genetic factors, or the

ISSN:0001-5652    

DOI:10.1159/000152356

出版商:S. Karger AG    

年代:1970

数据来源: Karger