Hb Moscva [ß24(B6)Gly→Asp (GGT>GAT), HBB: c.74G>A]: An Unstable Hemoglobin Newly Detected as a De Novo Mutation in a Mauritanian Patient.

Unstable hemoglobins (Hbs) are a group of Hb disorders that could be the origin of chronic hemolytic anemia. Most of these disorders are caused by point mutations taking place in the globin genes and affecting the stability of the Hb molecule. They are inherited as autosomal dominant diseases and described worldwide. Herein we report a new observation of an unstable variant in the Mauritanian population. The patient was a young girl of Mauritanian origin. She presented with chronic hemolytic anemia with an unknown etiology after being referred to several medical centers. Laboratory investigations based on routine analyses, capillary electrophoresis (CE), cation exchange high performance liquid chromatography (HPLC) and DNA sequencing revealed an abnormal unstable Hb known as Hb Moscva [ß24(B6)Gly→Asp (GGT>GAT), HBB: c.74G>A] that occurred as a de novo mutation newly detected in an African girl of Mauritanian origin.

HLA class I (-A, -B, -C) and class II (-DR, -DQ) polymorphism in the Mauritanian population.

BACKGROUND: HLA antigens have been widely studied for their role in transplantation biology, human diseases and population diversity. The aim of this study was to provide the first profile of HLA class I and class II alleles in the Mauritanian population. METHODS: HLA typing was carried in 93 healthy Mauritanian blood donors, using single specific primer amplification (PCR-SSP). RESULTS: Occurrences of the main HLA class I (-A, -B, -C) and class II (-DR, -DQ) antigens in the general population showed that out of the 17 HLA-A allele groups detected, five main HLA-A allele groups: A*02 (18.42%), A*01 (14.04%), A*23 (14.04%), A*30 (13.16%) and A*29 (12.28%) were the most common identified along other 12 relatively minor allele groups. Twenty three allele groups were observed in the locus B of which B*07 (13.46%) was the most prevalent followed by B*15, B*35, B*08 and B*27 all, with a frequency between 7 to 8%. Three prevalent HLA-C allele groups (C*02: 35.09%, C*07: 20.19% and C*06: 13.6%) were detected. The main HLA class II observed allele groups were: DRB1*13 (27.42%), DRB1*03 (24.73%), DRB1*11 (13.98%), DQB1*03 (36.03%), DQB1*02 (22.06%) and DQB1*05 (18.8%). Except for few haplotype in class I (A*02-B*07: 4.45%, A*02-C02: 10%, A*23-C*02: 8.8%, B*07-C*02: 8.8%, B*15-C*02: 8.8%) and in class II (DRB1*13-DQB1*06: 11.94%, DRB1*03-DQB1*02:11.19% and DRB1*03-DQB1*03: 10.45%), the majority of locus combination were in the range of 2-3%. A single predominant haplotype C*02-DRB1*03 (16.67%) was found. CONCLUSIONS: These results, in agreement with previous data using different tissues markers, underlined the ethnic heterogeneity of the Mauritanian population.

Hb S [ß6(A3)Glu→Val, GAG>GTG] and ß-globin gene cluster haplotype distribution in Mauritania.

Of 1050 Mauritanian blood donors screened from the two main racial groups, i.e., the Moors and Black Africans, 60 were found to carry Hb S [ß6(A3)Glu→Val, GAG>GTG], giving a global frequency of 5.71%. The prevalence observed in the Black African Mauritanians (10.69%) is almost five times that found in the Moor group (2.25%). Four of the five main ß(S) haplotypes were detected in this study: Senegal (77.8%), Benin (8.8%), Arab-Indian (5.5%) and Bantu (4.4%). These data showed that Hb S is a serious public health problem in Mauritania. They also confirm the ethnic heterogeneity of the Mauritanian population.