Two female patients are described who were, following difficulties in blood cross matching, found to be homozygous for the rare Rhesus --D-- gene complex. Both patients had formed Rh antibodies, one provoked by transfusions and the other by three pregnancies. The parents' relationship of one could easily be traced. Family tracing of the other patient was unsuccessful but her parents were probably related. The frequency of the --D-- haplotype in Icelanders was estimated 1/214 by investigating 750 families of disputed paternity.

Aged↗

PubMedDate not supplied

Linkage of an X-chromosome cleft palate gene.

Many congenital malformations, such as cleft palate and neural tube defects, have a multifactorial origin involving both environmental and genetic factors. Conditions such as these may be exclusively monogenic, polygenic or environmental, but in most cases both genetic and environmental factors are involved. This study describes the sub-chromosomal localization of a single gene defect causing cleft palate and ankyloglossia (tongue-tied) in a large Icelandic family. This defect is a model for the analysis of other neural-crest malformations that show a more complex multifactorial inheritance pattern.

Cleft Palate↗

PubMedDate not supplied

Immunohistochemical demonstration of amyloid P component in cerebro-vascular amyloidosis.

The presence of amyloid P component (AP) in cerebral amyloid deposits was sought using a direct immunoperoxidase technique. AP was detected in the amyloid deposits in the vessel walls but was absent from the intracerebral plaques in tissue from patients with senile cerebral amyloidosis. AP was also present in the amyloid deposits in the vessel walls of patients with the Icelandic form of hereditary cerebral haemorrhage associated with amyloidosis.

Amyloid↗

PubMedDate not supplied

Serum esterases of Icelanders. I. A "silent" pseudocholinesterase gene in an Icelandic family.

During an investigation of cousin marriages in Iceland, five brothers and sisters were found to be homozygous for the "silent" allele of plasma cholinesterase. Clinical information on two family members is presented and discussed, and the possibility of the presence of a "nearly silent" plasma esterase allele, in one of the family units investigated, is suggested.

Alleles↗

PubMedDate not supplied

Immunohistochemical characterization of the amyloid deposits and quantitation of pertinent cerebrospinal fluid proteins in hereditary cerebral hemorrhage with amyloidosis.

Cystatin C, a protein inhibitor of lysosomal cysteine proteinases, was demonstrated by immunohistochemical techniques to be present in the birefringent amyloid deposits of the small arteries in the cerebrum, cerebellum, and leptomeninges of 10 Icelandic individuals with hereditary cerebral hemorrhage with amyloidosis. Specimens from other organs were investigated in one of the patients, and amyloid angiopathy characterized by an immunoreactivity of cystatin C was found in a submandibular lymph node. No immunoreactivity of amyloid fibril protein AA, kappa or lambda immunoglobulin light chain, or prealbumin was observed. Significantly low cerebrospinal fluid concentrations of cystatin C were found in all 9 investigated individuals with hereditary cerebral hemorrhage with amyloidosis. The concentrations of beta 2-microglobulin, albumin, and IgG in the cerebrospinal fluid were within normal limits. Isoelectric focusing showed that cystatin C from the cerebrospinal fluid of 9 patients with hereditary cerebral hemorrhage with amyloidosis had an isoelectric point identical to that of normal individuals. This investigation demonstrates that hereditary cerebral hemorrhage with amyloidosis may be diagnosed by two laboratory methods: immunohistochemical investigation of cystatin C in brain tissue specimens and quantitation of cystatin C in cerebrospinal fluid.

Adult↗

PubMedDate not supplied

Localization of a mutant gene for cleft palate and ankyloglossia in an X-linked Icelandic family.

Common congenital malformations such as cleft lip and cleft palate are in most cases multifactorial in origin, involving both environmental and genetic components. Molecular biology techniques have enabled the successful chromosomal localization of many mutant genes from disorders that exhibit simple Mendelian segregation, whether autosomally dominant (e.g., Huntington's disease), autosomal recessive (e.g., cystic fibrosis), or X-linked (e.g., Duchenne muscular dystrophy). Studying the genetic aspect of multifactorial disorders is more complex. It requires a model family or families within which the common multifactorial phenotype is displayed as a single gene defect. Such a model has been recently exploited in the form of a large Icelandic family (over 280 members) exhibiting X-linked secondary cleft palate (CP) and ankyloglossia (A) (tongue-tied) as a single gene mutation. Using this family and the large bank of well-characterized DNA probes available for the human X chromosome, the gene for CP + A was localized by linkage analysis to Xq13-q21.1 (LOD score = 3.07, linked to anonymous probe DXYS1). Further fine mapping, using other X probes from this region (confirmed by analysis of DNA from a deletion cell-line) has placed the gene between markers DXYS12 and DXS17 (LOD score = 4.1) at Xq21.3-q22. The approximate distance between these two probes is 5 centimorgans (cM), equivalent to approximately 5 million base pairs. Now that the limits of genetic linkage have been fully tested and there are two markers flanking the defect locus, strategies are being pursued to clone the gene responsible.(ABSTRACT TRUNCATED AT 250 WORDS)

Cleft Palate↗