Assessment of the role of a general clinic of a health centre in a rural Jamaican community

A health centre served a defined and censussed rural community. Patients' attendances at the general clinic are expressed as attendance rates for each age/sex group in the community. The diseases most commonly diagnosed in each group of patients and the patients' use of other health services are described (AU)

Beta-chain variants in Jamaica newborns

In an electrophoretic study of 15,661 Jamaican cord bloods, 8 rare beta-chain variants were found in 18 subjects in addition to the common beta-chain variants, Hb S and Hb C. The heterozygote frequencies for Hb S and Hb C were 10.1 percent and 3.7 percent respectively. The most frequent of the rare beta-chain variants were Hb Korle Bu (beta 73 Asp leads to Asn) (7 cases) and Hb O su-Christiansborg (beta 52 Asp leads to Asn) (3 cases). One new beta-chain variant, Hb Caribbean (beta 91 Leu leads to Arg) was found. (AU)

Haemoglobin Spanish Town alpha27 Glu replaced by Val (B8)

A new alpha chain variant Hb Spanish Town, a27 Glutamic acid-Valine, awas detected in the cord blood of a Jamaica Negro infant. In the mother the adult component (a2 Spanish TownB2) has an electrophoretic mobility between haemoglobins S and F at alkaline pH and measures 11.0-12.0 percent of the total haemoglobin. (Summary)

Variations in globin chain synthesis in hereditary persistence of fetal haemoglobin

Globin synthesis was studied in four Negro families including 10 members with Hb A-HPFH and four with Hb S-HPFH. The á/O specific activity ratios in 10 of these patients with Hb A-HPFH heterozygotes were similar to those of the control group. In two patients with Hb A-HPFH, the á/O ratio was slightly decreased in one (0.84) and clearly decreased in another (0.78). In two of the patients with Hb S-HPFH the ratios were clearly decreased (0.71 and 0.75). The extended range of á/O ratios in these 14 patients is similar to that of Negro patients with á-thalassaemia trait. These studies indicate that a decreased á/O ratio may be found in HPFH, as well as in á-thalassaemia. Bone marrow globin synthesis was measured in two patients with Hb S-HPFH and decreased peripheral blood á/O ratios, and in one with Hb A-HPFH and a normal peripheral blood á/O ratio. In each patient the (á+y)/O ratio of radioactivities as well as the á/O specific activity ratio was close to I and therefore balanced, indicating more rapid decay of á-chain synthesis relative to O-chain during red cell maturation or extremely rapid destruction of newly synthesized excess O-chains in the bone marrow.(Summary)

Gamma chain variants in Jamaica newborns

15,661 cord bloods from Jamaican infants were examined for abnormal hemoglobins using alkaline cellulose acetate electrophoresis for the initial screening, supplemented by acid agar gel electrophoresis for samples exhibiting abnormal hemoglobin bands. Of the 16 electrophoretic variants which were detected, six were fully characterized and found to be: four Hb F Port Royal (alpha2 Ggamma2 125 Glu replaced by Ala) and two Hb F Victoria Jubilee (alpha2Agamma2 80 Asp replaced by Tyr). The Hb F Port Royal samples each constituted about one eighth of the total Hb F as did seven additional samples presumed to be Hb F Port Royal. The infants with this variant exhibited no special hematological characteristics or other consistent associations. Both Hb F Victoria Jubilee samples ocurred in somewhat lower proportions of the total Hb F compared with Hb F Port Royal and exhibited an apparent increase of free alpha chains in the whole hemolysate. The data available on detectable gamma chain variants suggest that a specific point mutation may occur in either a HbGgamma or a HbAgamma locus. (AU)

Beta-thalassaemia of clinical significance in adult Jamaican negroes

Over a 9-year period, three adult Negro patients with á-thalassaemia of clinical significance were recognized out of approximately 185,000 new adult patients attending the University Hospital. These patients, ages 15-58 years, have clinical and haematological characteristics within the spectrum of á-thalassaemia intermedia; which in this paper refers to phenotypes resulting from defects in á-chain synthesis clinically intermediate between classical Cooley's anaemia and á-thalassaemia trait, genetic classification being dependent on family study. Family studies established the presence of two á-thalassaemia genes conclusively in one case (proposita, family A); presumptively in another(propositus, family C); while in the remaining subject (proposita, famaily B), who has two similarly affected siblings, homozygosity is suspected, but not proven by family study. In simultaneous Fe and Cr studies, estimates of effective erythropoiesis are in reasonable agreement with measurements of red cell destruction.(Summary)

Globin synthesis in the Jamaican Negro with beta-thalassemia

Globin synthesis was studied in three Jamaican Negro families with 18 heterozygotes and 5 homozygotes for beta-thalassemia. Synthesis of the beta chain of Hb A in the peripheral blood of heterozygotes was equal to that of the alpha-chain in 10 patients and was decreased in the remainder. In one patient with Hb C beta-thalassemia the beta/alpha ratio was normal. These findings were similar to those in American Negroes, but differed from those in Caucasian with beta-thalassemia trait, in each of whom the beta/alpha ratio was decreased. Globin synthesis was balanced in the bone marrows of Negro and Caucasian heterozygotes. Despite the milder clinical disease in Negro homozygotes as compared to Caucasian patients, the beta/alpha ratios were similar in both groups. The presence of alpha-thalassemia combined with beta-thalassemia in Negro heterozygotes is not a likely explanation for the high incidence of balanced globin synthesis ratios. The expression of relative beta to alpha chain synthesis in Negro heterozygotes appears to be modified by a factor which is not linked to the delta-chain locus. The nature of this factor is not known at present.(Summary)

Hemoglobin F Port Royal (alpha2G gamma2 125 GLU leads to Ala)

A Gy-chain variant, Hb F Port Royal, with an electrophoretic mobility intermediate between Hb S and Hb C was found in a Jamaican-Negro infant, and made up to 14-15 percent of the total Hb F. A glycinamidation procedure was employed to aid in the determining the amino-acid residu substitution of gamma 123 Glu leads to Ala, and the presence of glycine in position 136. (AU)

The prevalence of the rarer inherited haemoglobin defects in adult Jamaicans

The prevalence of several haemoglobin defects, including the traits for á-thalassaemia (0.8 percent), hereditary persistence of foetal haemoglobin (0.2 percent) and the abnormal delta change haemoglobin, Hb B2 (2.4 percent), were determined from the combined results of surveys conducted on adults in a suburban and a rural community. Mean Hb A2 levels of 2.6 ñ0.4 percent, 5.3 ñ0.5 percent and 2.0 ñ0.2 percent were found in 639 Hb A homozygotes, seven á-thalassaemia traits and three traits for hereditary persistence of of foetal haemoglobin (HPFH), respectively. Levels of alkali resistence haemoglobin (A.R.Hb) ranged from 0.6 to 7.3 percent in the thalassaemia traits and were 21.0, 19.0 and 16.0 percent in the three HPFH traits; the remaining 770 subjects in whom A.R.Hb was measured had a mean value of 0.6 ñ0.6 percent. (AU)

The prevalence of iron deficent erythropoiesis and anaemia in a rural Jamaican community

Serum iron, iron binding capacity and transferrin saturation were measured in 389 predominantly Negro adults from an agricultural community in Jamaica. The relationships between iron measurements and several other red cell characteristics were investigated and the possible influence of common inhereted red cell defects was examined. Iron deficient erythropoiesis (transferrin saturation <15 percent) occurred in only a third of anaemic subjects. Values of total iron binding capacity were considerable lower than those found in a large random sample from Wales (Jacobs et al, 1969). These findings are considered in relation to the nutritional status of the population (Summary)