Home Genetics - Biochemistry - Pathologies
HLA class I in 3 West African ethnic groups  
Somatomedin C (IGF-1)
Immunoglobulin enhancer HS1,2 polimorphism
Duplication in exon 10 of human chitotriosidase gene
Clinical presentation: HbS and HbC
Modification of frequency of HbS and HbC
Confirmation of 2 beta globine pseudogenes markers
Chitotriosidase in Sicilians  
G-6PD and Sickl cell
MTHFR1 Burkina Faso
Fitness HbS and HbC
Anthropological consideration on prevalence and fitness of β C and β S
HbC and Malaria
HbC and HbS  

Genetic pathologies

Currently, more than three thousand types of hereditary diseases have been identified. Genetic diseases have taken a heavy tall among the global population, source of child mortality or severe disability.

  • Currently, nearly one hundred million (100,000,000) people are affected by genetic mutation, coding therefore for glucose-6-phosphate dehydrogenase, which leads to favism.
  • Nearly two hundred and fifty million (250,000,000) people suffer from several types of anemia due to genetic mutations.
  • In developed countries, one third of pediatric hospitalizations are associated with genetic disorders.
  • Mucoviscidosis, source of cystic fibrosis, affects about one child over 2 500 children among the Caucasian population. Four percent (4%) of the population bear the mutated gene of the cystic fibrosis (CF).
  • In Africa and America, sickle cell disease alone kills nearly one hundred thousand of black children yearly excluding multi-factorial genetic and cystogenic diseases.
  • In Burkina Faso, more than 25% of the population have a mutation of the beta chain of hemoglobin (ßS SSC). Nearly 5% of children are suffering from various forms of sickle cell disease (Hb SS or Hb SC).

The hemoglobin, the main component of red blood cells is a tetramer molecule made of 67,000 daltons comprising four subunits called globins. Each subunit consists of an iron atom coordinated by a porphyrin, a protein chain and possibly a small molecule such as CO (carbon mono-oxide), NO (nitrogen mono-oxides) or O2 (molecular oxygen). The hemoglobin changes from the embryonic stage to adulthood: - embryonic hemoglobin Hb Gower1 (a2 e2) and Hb Gower 2 (a2 e2) - fetal hemoglobin HbF (a2 g2) - and adult hemoglobin Hb A (?a2 b2??) and Hb A2? (a2 d2?). The sickle cell disease which is a hemoglobinopathy, annually kills nearly 100,000 black children in the world. There are more than 600 variants of hemoglobin. The Bs form is due to the mutation of the sixth codon of the first exon of the globin b gene (GTG GAG), leading to the replacement of the glutamic acid by the valine. As to the bc form, it is due to missense mutation b (GAG to AAG) leading to the replacement of the glutamic acid by lysine in 6-like position. Individuals with major sickle cell syndrome (SDM): SS homozygotes and double heterozygotes SC may suffer from ischemic due to hypoxia. They suffer from splenomegaly and also often suffer from anemia without any iron deficiency.
Individuals who bear the hemoglobins: AS, AC, DC are not sick but they carry a sickle cell characteristic.

The hemoglobin electrophoresis on cellulose acetate using a densitometer gives the following rates:

  • Hemoglobin A (HbA): 60 -55%
  • Hemoglobin S (HbS): 45-40%
  • Hemoglobin A2 (HbA2): 2-3%

From formal Mendelian genetics to molecular genetics, researchers of the twentieth century have made a major scientific progress by using modern tools of molecular biology. Indeed, genetic engineering, which is the direct application of molecular genetics, has paved new paths full of hope: from primitive agriculture to "geneculture", the in vitro culture of genes by cloning or PCR, the study of the human genome to the "Moleculture", the production of therapeutic proteins by plants and microorganisms used as bio-reactors, we then have biotechnology, gene therapy, both reproductive and therapeutic cloning, etc.

The application of molecular genetics to population genetics has allowed identifying several major genetic markers which allow us to see the interaction between the legacy of the genetic heritage, the evolution, the natural selection and adaptation
Schéma de transmission génétique de la Drépanocytose
Ces 4 couples ci-dessus peuvent-ils se marier sans transmettre la drépanocytose à leurs enfants ?
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Ces 2 couples ci-dessus peuvent-ils se marier sans transmettre la drépanocytose à leurs enfants ?
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