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Biomedical subjects

T Grimm

Publications and source records attributed to T Grimm.

105 records · Page 6Linked to original sources
PubMed1978

Cri-du-chat syndrome in a child with a 5/15 translocation and interstitial centromeric heterochromatin.

A child is described with most of the typical clinical features of the cri-du-chat syndrome. G- and C-banding studies revealed the karyotype 45,XX, -5, -15, +tdic (5;15) with the loss of short arm material from chromosome 5. Centromeric heterochromatin of the translocated No. 15 is still present in the translocation chromosome. However, no silver precipitation after AgNO3-staining was observed on the translocation chromosome, thus indicating a loss or genetic inactivation of the NOR-region of the translocated No. 15. These cytogenetic results and their possible relationship to the cri-du-chat phenotype are discussed.

Centromere↗
PubMed1977

Evidence for preferential X-chromosome inactivation in a family with Fabry disease.

Severe clinical signs of Fabry disease were observed in four of eight heterozygous daughters of a male patient. Activities of alpha-galactosidase A in serum, white blood cells, and hair roots of the manifesting carriers were markedly lower than 50% of normal. These findings are not easy to interpret in terms of random X inactivation alone; several alternative models including nonrandom (preferential) X inactivation are discussed.

Blood Group Antigens↗
PubMed1976

Fabry's disease: heterozygote detection by hair root analysis.

Fabry's disease (angiokeratoma corporis diffusum) can be diagnosed by determination of alpha-galactosidase activity in single hair roots. A technique has been developed permitting subsequent analysis of enzyme activity and protein content of hair root cells. We have applied this method examining 8 obligatorily heterozygous sisters as well as their 5 daughters and 10 sons. Especially for identification of heterozygotes, the method described proved to be easy and reliable.

Clinical Enzyme Tests↗
PubMed1975

Heterozygote tests and genetic counseling in maple syrup urine disease: an application of Baye's theorem.

The discriminatory power of a quantitative heterozygote test for Maple Syrup Urine Disease (MSUD) which we have been using is analyzed on the presumption that a single rare mutant allele is involved in MSUD. Bayes theorem then predicts that only a small portion of persons from the general population with activities in the heterozygous range really are heterozygotes. In addition, overlap of heterozygous and normal homozygous activity distributions requires rather high activities in first-cousin matings of a patient's sib in order to obviate the necessity for prenatal diagnosis. Thus, the principle emerges that quantitative heterozygote tests for rare autosomal recessive diseases cannot fulfill the task they were designed for.

Bayes Theorem↗
PubMedDate not supplied

[Holt-Oram syndrome in combination with reciprocal translocation, lung hypoplasia and cardiomyopathy].

A now two years old girl had developed respiratory insufficiency shortly after birth requiring prolonged artificial ventilation. A hypo- and dysplasia of the right lung was identified as the underlying cause. Further diagnostic evaluation revealed a malformation of bones, i.e. shortness of the humerus, aplasia of the radius, shortness of the ulna and a congenital anlage of four metacarpal bones in fixed malposition. In addition, an atrial septal defect of the sinus venous type with left-to-right shunting was present. This, in combination with the sceletal abnormalities pointed to the diagnosis of Holt-Oram syndrome. In her first year of life the patient also developed a hypertrophic non-obstructive cardiomyopathy. Cytogenetic analysis of her family revealed a reciporke translocation between chromosome 1 and 11 (t -1, -11 (1p13, 11q13)) in the patient herself, her father and the father and a sister of her father. However, this finding as well as the hypertrophic cardiomyopathy has to be regarded as being independent from Holt-Oram syndrome.

Abnormalities, Multiple↗
PubMedDate not supplied

[Importance of germ cell mosaic for genetic counseling of families with Duchenne and Becker muscular dystrophy].

Germ cell mosaics were demonstrated in Duchenne's and Becker's muscular dystrophy by molecular genetic methods. These findings affect risk estimates in these x-chromosomal muscular diseases. The mutation-selection equilibrium for x-chromosomally lethal inheritance for determining the a priori probability for risk estimate according to the Bayes theorem must therefore be redefined to take the germ cell mosaic problem into account. Taking Duchenne's and Becker's progressive muscular dystrophy as an example, the article explains how the estimation of the heterozygote risk in women seeking advice changes in different family situations.

Bayes Theorem↗
PubMedDate not supplied

[Holoprosencephaly--clinical picture and genetic counseling in 6 cases].

Inadequate midfacial and forebrain development may result from constitutional chromosome aberrations, gene defects and, possibly, from as yet unidentified terato-genetic agents. The spectrum of clinical manifestations ranges from cyclopia with grossly incomplete organogenesis of the forebrain to apparently minor deviation from normal midface morphogenesis presenting as hypotelorism or absence of the philtrum. Such minor facial dysmorphias may, however, be likewise accompanied by severe anomaly in brain development and function. We report six cases of holoprosencephaly defects in children without demonstrable chromosomal anomalies. The presenting clinical symptoms in these cases were anomalies of cranio-facial shape, hypotelorism; nasal and ocular malformations, as well as median clefts. Some cases presented additional defects in extra craniofacial regions. Two infants who survived for several hours showed evidence of forebrain defects on CT-scans. Three of the cases suggest autosomal-recessive inheritance with 25% recurrence risk on the basis of proven or highly probable parental consanguinity. The remaining, presumably sporadic cases carry a low empirical recurrence risk. Three of the six cases received direct or indirect hormone treatments during early pregnancy.

Abnormalities, Multiple↗
PubMedDate not supplied

[X-chromosome recessive lymphoproliferative disease (XLP): molecular genetic studies].

X-linked lymphoproliferative disease (XLP) is a rare worldwide occurring inherited immunodeficiency which is triggered by Epstein-Barr virus infection. Clinical phenotypes in 21 affected males from 5 German families with XLP ranged from severe and fatal infectious mononucleosis (57%) to acquired hypogammaglobulinaemia (28%), malignant lymphoma (28%), aplastic anaemia (19%) and hypergammaglobulinaemia M (19%). Molecular genetic studies with various polymorphic X-chromosomal DNA markers in 14 XLP families mapped the XLP gene locus to Xq25-q26. Haplotype analysis enables detection of XLP-positive and XLP-negative males already before EBV-infection as well as diagnosis of healthy female carriers within XLP families.

Child↗
PubMedDate not supplied

Mapping undetected mutations within a gene-evidence for two preferential regions in the DMD gene.

A maximum-likelihood method is developed to estimate the frequency distribution of undetected mutations (presumably point mutations, small deletions, insertions) along a gene, where the gene extends over a long stretch of DNA. In each family, the point of the mutation is potentially at a different location within the gene. In this sense, there is genetic heterogeneity among families and the method estimates the proportion of families whose mutation is at (or in the vicinity of) a given point inside the gene. Our method is applied to a sample of 75 families with Duchenne muscular dystrophy in which the disease mutation remained undetected. We find two preferential regions for these undetected mutations, with an estimated 85% of families having their mutation in one region and the remaining 15% of families in the other. The new method is expected to be useful in finding small mutations in any of the currently known large genes.

Chromosome Mapping↗