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F F Chehab

Publications and source records attributed to F F Chehab.

42 records · Page 3Linked to original sources
PubMed1987

Gene deletions correlate with the development of alloantibodies in von Willebrand disease.

Among all patients with von Willebrand disease (vWD), alloantibodies to von Willebrand factor (vWF) have been described only in severe vWD (type III). The relationship between the development of alloantibodies and the nature of the genetic lesion in vWD is not known. In hemophilia B, large deletions within the factor IX gene appear to correlate with the occurrence of alloantibodies, whereas in hemophilia A no such correlation is apparent. We have studied 19 patients with severe recessive vWD (type III) and 19 with autosomal dominant vWD (type I) by Southern blotting with probes encompassing the full 9 kilobases (kb) of the vWF cDNA. Two apparently unrelated patients were shown to have large deletions within the vWF gene. Both patients had severe vWD (type III) and were the only patients among those studied that had inhibitory alloantibodies to vWF. The extent of deletion was similar in both patients, corresponding to at least the 3'-7.4 kb of the vWF cDNA. The deletion in each patient was estimated to exceed 110 kb. In addition, the localization of the vWF gene to chromosome 12 was confirmed, and a homologous sequence on chromosome 22 was identified.

Chromosome Aberrations↗
PubMed1987

The molecular basis of beta-thalassemia in Lebanon: application to prenatal diagnosis.

A study of the molecular lesions of beta-thalassemia in Lebanon revealed the presence of eight different mutations in 25 patients with Cooley's anemia. The IVS1 position 110 mutation predominated with a frequency of 62% and was almost invariably associated with Mediterranean chromosome haplotype I. Five other mutations commonly found in the Mediterranean area occurred with frequencies of 2% to 8%. In addition a G----C substitution in IVS1 position 5 (a lesion previously found in Chinese and Asian Indians) was demonstrated in a patient with Mediterranean haplotype IX. A new mutation at codon 29 was found in two other patients with haplotype II. The characterization of these beta-thalassemia mutations should allow the implementation of a prenatal diagnosis program in that country.

Globins↗
PubMed1986

Spontaneous mutation in beta-thalassaemia producing the same nucleotide substitution as that in a common hereditary form.

The molecular basis of a spontaneous mutation causing beta-thalassaemia in a boy of north European descent was characterised. The codon at the beta 39 position had mutated from CAG (glutamine) to the stop codon TAG. This nonsense mutation occurs commonly in a hereditary form of beta-thalassaemia in the Mediterranean area; its production by a spontaneous mutation suggests that this region of the beta-globin gene is a mutational hot spot.

Base Sequence↗
PubMed1984

Globin synthetic ratios in homozygous beta-thalassemia patients from Lebanon.

We have studied patients with beta-thalassemia from a Lebanese population having a high rate of consanguineous matings. This population exhibits both elevated and normal levels of Hb A2 associated with high levels of Hb F in homozygotes. The clinical course of the anemia suggests that this population consists of the severe Mediterranean type. Twenty-three unrelated homozygous beta-thalassemia patients investigated for globin synthetic ratios, consisted of 18 beta+ and 5 beta 0 with a non-alpha/alpha range of 0.158-0.465 and 0.25-0.41, respectively. The percentage of G gamma chains in Hb F was determined for 21 of these patients and a mean value of 59% G gamma chain content was found.

Electrophoresis, Disc↗