We have identified the beta-thalassaemia alleles in nearly all known Turkish Cypriot beta-thalassaemia homozygotes and in over 700 Greek Cypriot beta-thalassaemia heterozygotes living on the island of Cyprus. The data confirmed earlier observations that the IVS-I-100 (G-->A) mutation is present for about 74-80%, while three other alleles [IVS-II-745 (C-->G), IVS-I-6 (T-->C), IVS-I-1 (G-->A)] occur at frequencies of 5-8%. Nearly identical percentages were observed for the two Cypriot groups, quite different from those for beta-thalassaemia patients from Greece and Turkey. This suggests close contacts between the two Cypriot communities during many centuries without a major recent influence from Greek or Turkish beta-thalassaemia carriers.

We have determined the beta S haplotypes in 709 patients with sickle cell anemia, 30 with SC disease, 91 with S-beta-thalassemia, and in 322 Hb S heterozygotes from different countries. The methodology concerned the detection of mutations in the promoter sequences of the G gamma- and A gamma-globin genes through dot blot analysis of amplified DNA with 32P-labeled probes, and an analysis of isolated Hb F by reversed phase high performance liquid chromatography to detect the presence of the A gamma T chain [A gamma 75(E19)Ile----Thr] that is characteristic for haplotype 17 (Cameroon). The results support previously published data obtained with conventional methodology that indicates that the beta S gene arose separately in different locations. The present methodology has the advantage of being relatively inexpensive and fast, allowing the collection of a vast body of data in a short period of time. It also offers the opportunity of identifying unusual beta S haplotypes that may be associated with a milder expression of the disease. The numerous blood samples obtained from many SS patients living in different countries made it possible to compare their hematological data. Such information is included (as average values) for 395 SS patients with haplotype 19/19, for 2 with haplotype 17/17, for 50 with haplotype 20/20, for 2 with haplotype 3/3, and for 37 with haplotype 31/31. Some information on haplotype characteristics of normal beta A chromosomes is also presented.

We have analysed the alpha-globin gene defects present in several members of a large family from Southern Turkey. One deletional alpha-thalassaemia-1 (type MED-II) was found in 10 subjects: this deletion is in excess of 26.5 kb and includes all zeta- and alpha-globin genes. Besides the common types of deletional alpha-thalassaemia-2 (-3.7 kb and -4.2 kb) we observed a nondeletional alpha-thalassaemia-2 that results from an A----G mutation (AATAAA----AATGAA) in the polyadenylation signal of the alpha 2-globin gene: the same A----G replacement is present in the psi alpha l gene. The mutation must cause a considerable alpha-chain deficiency as is evidenced by the haematological data for five members with Hb H disease due to a compound heterozygosity for alpha-thalassaemia-1 (MED-II) and the newly discovered poly A mutation. Several members had additional beta-chain abnormalities (Hb S, Hb D-Los Angeles, beta-thalassaemia); the 11 persons with a Hb S heterozygosity and various alpha-globin gene defects (-alpha/alpha alpha; alpha T alpha/alpha alpha, - -/alpha alpha, -alpha/-alpha and - -/alpha T alpha) showed a decrease in the level of Hb S that was directly related to the severity of the alpha-chain deficiency.

Haematological and genetic observations have been made on 71 SS Eti-Turk patients and their relatives from Cukurova (southern Turkey) and of immigrant families in The Netherlands. Similar data were collected for 25 Black patients and their relatives from Surinam, Netherlands Antilles, and Kenya. Haematological and clinical results were the same for both groups; the haemolytic anaemia in the Turkish patients was as severe as in the others. Haplotyping, involving nine restriction sites, identified haplotype 19 (Antonarakis et al, 1984) as the major type among the Eti-Turks; this chromosome has previously primarily been observed among SS patients from West Africa. The suggestion that the beta S-chromosome among Eti-Turks originates from that area is supported by a relatively high incidence of alpha-thalassaemia-2 (the 3.7 kb deletion), also frequently present in the Black population of West Africa, and by the absence of other major haplotypes, such as types 20 and 3, characteristic for the beta S-chromosome in the population of Central Africa and Kenya, and in Senegal, respectively. The Saudi Arabian type of beta S chromosome in association with the haplotype 19 beta S chromosome was present in only one Eti-Turk patient; this 30-year-old female was mildly affected and exhibited a high level of fetal haemoglobin.

The high rate of IDA raises serious concern about nutritional disease risks in the region. An inexpensive oral iron therapy and education as to the importance of iron for their health would help to provide optimal health for the population concerned, especially for mothers-to-be and children.