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Biomedical subjects

I Klisak

Publications and source records attributed to I Klisak.

9 recordsLinked to original sources

Assignment of the beta-subunit of rod photoreceptor cGMP phosphodiesterase gene PDEB (homolog of the mouse rd gene) to human chromosome 4p16.

The gene encoding the beta-subunit of rod photoreceptor cGMP phosphodiesterase (gene symbol PDEB, homolog of the mouse rd gene) is mapped to human chromosome 4 using somatic cell hybrids and further localized to the chromosome band 4p16 using in situ hybridization. A mutation in the mouse gene underlies the recessive trait of retinal degeneration in the rd mouse. Thus, the human homolog is a candidate for lesions causing retinal degeneration.

3',5'-Cyclic-GMP Phosphodiesterases

Prominent acrocentric chromosome satellites in child patients with mental retardation or psychiatric disorders; no IQ-satellite size correlation.

Child patients with mental retardation or psychiatric disorders were selected for the presence of prominent acrocentric chromosome satellites and highest or lowest IQ scores. No correlation was found between IQ scores, of which eleven were below IQ 54 and 16 above IQ 68, and the length of acrocentric short arm, satellite, stalk, or short arm material below the stalk. Conventional staining, quinacrine fluorescence, C banding and ammoniacal silver staining revealed the apparent same acrocentric short arm variation between patient and one parent in eight families studied. These findings suggest that the satellite variants were truly normal variants and not etiologically related to the developmental disorders seen in the patients.

Child

Phenotypic variation in two patients with a ring chromosome 22.

Two severely mentally retarded patients with a ring chromosome 22 presented with disparate phenotypes: one patient manifested only minimal dysmorphic features, whereas the other had a distinctive pattern of anomalies consisting of an abnormal skull configuration with mild maxillary hypoplasia, a large nose, thick full lips, a protruding tongue, lymphedema, hypotonia and an unsteady gait. The findings in these and previously reported patients indicate that a ring chromosome 22 is usually associated with moderate to severe mental retardation, with a range of dysplastic features from mild and nonspecific to more marked and distinctive.

Abnormalities, Multiple

The 9p-syndrome.

A 13-year-old boy with 9p- (p22 leads to pter) is reported. He had many features in common with previous 9p- cases, as well as several distinctive features including polydactyly and precocious puberty. Cytogenetic studies revealed a de novo deletion distal to ban 9p22, which was the reported site of chromosome break in 9 of the 10 previous 9p- cases. Evaluation of the human GALT enzyme suggests that its locus is not on the deleted segment.

Abnormalities, Multiple

Report of a trisomy 8p infant with carrier father.

This report describes an infant with fatal congenital heart disease, cleft palate, brain malformations, and trisomy 8p resultant from the paternal balanced reciprocal translocation, rcp(8;15) (p11;p11). Review of six previously reported trisomy 8p patients (resultant from parental balanced translocation in each instance) revealed severe mental retardation in five, short stature in all, and a variety of brain, skeletal, and cardiac defects. The features of the seven trisomy 8p patients reviewed here are not sufficiently similar to suggest a distinct dysmorphic syndrome. In addition the features differ from those in the trisomy 8 mosaicism syndrome, in which the mental retardation and malformations are generally less severe.

Abnormalities, Multiple

18p--syndrome resulting from 14q/18q 'dicentric' fusion translocation.

A child with nasal hypoplasia, growth and developmental delay, and 18p--due to 14q/18q apparent dicentric fusion is reported. Review of ten previously reported patients with 18p--due to fusion translocations involving the long arm of chromosome 18 reveals clinical features ranging from arrhinencephaly to minimal dysmorphic changes and mild retardation. This spectrum of clinical expression is similar to that seen in patients with partial 18p deletions. Since the same range of clinical features is observed whether there is partial or apparent total deletion of 18p, it is suggested that only a distal segment of the short arm of chromosome 18 may be etiologically related to the clinical phenotype in the 18p--syndrome.

Child, Preschool