Five cases of severe hydrops and erythroblastosis fetalis in association with a large amount of Hb “Bart’s,” all of Chinese origin, are described. The following characteristic clinical and hematologic symptoms were found. There were generalized hydrops, ascites and gross enlargement of the liver. The spleen, however, was not ahvays enlarged. The placenta was large and friable. Severe erythroblastosis of the blood was always found, with reticulocytosis, many target cells and thin cells. The MCV of the red cells was very high. The cells showed an interesting sickling phenomenon. No evidence of isoimmunization was found. In eight parents examined, no abnormal hemoglobin was detected, and alkali-resistant hemoglobin and hemoglobin A2 were not found to be increased. Their blood showed microcytosis of the red cells cxcept in one father and one mother. In this mother, however, the blood was examimied after a blood transfusion. It is thought probable that these were cases of homozygous alpha-chain thalassemia.
Newborns were examined for the presence of slow-moving haemoglobin components, tentatively designated X components and previously found in a group of Hb H disease in which invariably one of the parents of each patient had the same slow-moving Hb X components also. Structural studies showed that the abnormal haemoglobin in Chinese was identical with Hb Constant Spring, an c-chain variant. Newborns with Hb Bart’s and slow-moving X components invariably had one parent with the X components also. When the child grew older Hb Bart’s disappeared while the Hb X components remained in the blood. The homozygous state for the X components was found in a Malay boy through his newborn brother who had the X components in addition to Hb Bart’s and had both parents with the X components. One other Malay baby had the X components and Hb A2 Indonesia inherited from the parents. The present study of newborns also showed that Hb Bart’s can accompany different abnormalities of haemoglobin production, involving alpha-chains, beta-chains as well as gamm-chains. Its presence in cord blood is, therefore, not specific for alpha-thalassaemia
Key Words: Haemoglobinopathies; Hb Bart’s; Slow-moving Hb X; Thalassaemia
A survey of abnormal haemoglobins and hereditary ovalocytosis was carried out among 629 Malays of Minangkabau descent in the Ulu Jempul District of Kuala Pilah, in the state of Negri Sembilan in West Malaysia.. Several abnormal haemoglobins were found with the following frequencies: Hb E 5.25%, Hb CoSp 2.38%, Hb A2 indonesia 0.80%, a fast moving Hb with a Mobility between A and Bart's 0.64% and Hb Q 0.16%. Hereditary ovalocytosis was found in 13.2% of these people. None of the persons with hereditary ovalocytosis had any evidence of haemolysis.
Blood samples, demographic and cultural data were collected from seven settlements of Semai Senoi, a swidden farming ethnic group of Malaysia. Three genetic loci (ABO blood group, hereditary ovalcytosis, and hemoglobin) were analyzed in a total sample of 546 individuals. These data indicate a considerable degree of genetic microdifferentiation in this area of the Semai distribution. Parent-offspring birthplace data (analyzed by means of a migration matrix) and settlement histories show that settlements are not strongly isolated. Genetic differences in the study area demonstrate a reasonable correspondence with migration and the history of the settlements. Genetic convergence also occurs through the addition of migrant groups to established populations leading to new patterns of marriage between donor and recipient groups. The genetic structure of the total Semai population through time thus comprises a mosaic of shifiting allele frequencies in a series of semi-isolated local populations.
The Land and Sea Dayaks of Sarawak were surveyed for several erythrocyte enzymes. The gene frequency of 6PGDC in 132 Land Dayaks and 127 Sea Dayaks were 0.045 and 0.047, respectively. The gene frequency of PGM1-1 IN 285 Land Dayks and 240 Sea Dayaks were 0.716 and 0.779, respectively. The ADA2 gene frequency in 283 Land Dayaks and 188 Sea Dayaks were 0.154 and 0.090. ADA 5-1 was found once in the Land Dayaks and once in the Sea Dayaks. AK 2-1 was found once in 221 Sea Dayaks but not in any of 270 Land Dayaks. No PHI, LDH or CA variants were found among the Land or Sea Dayaks.
Human alcohol dehydrogenase ADH2 and ADH3 were investigated in liver and stomach specimens of Chinese and Indians from West Malaysia. Eight-nine percent of the Chinese carry the atypical ADH2 type, a proportion very similar to that reported in Japanese. However, among 43 Indian specimens there was not a single case of atypical ADH2. In Indians, the gene frequency of ADH13 is 0.64 and of ADH23 0.36, similar to the frequencies in Caucasians, whereas in Chinese, the gene frequency for ADH13 and ADH23 is 0.91 and 0.09, respectively. We also report some unusual enzymatic characteristics in the course of our study.
Most of the population in certain areas of Melanesia have one alpha-globin gene deletion (alpha thal2). It is thought that the high frequencies of alpha thal2 in this population is due to a selective advantage given by malaria infection to carriers of alpha thal2. We are interested in neighboring Polynesia which, although adjacent to Melanesia, has always been free of malaria due to the absence of the vector anopheles. We studied 60 Polynesian Samoans and 150 Malaysians by restriction endonuclease gene mapping using Eco RI, Bam HI, and Bgl II and hybridization to 32P-labeled alpha-globin gene probe. Seven among the 60 (11.7%) Samoans had triplicated alpha-globin loci type 1, while none had alpha thal2. On digestion with Bgl II the third alpha-globin gene was found in an additional 3.7 kb fragment in all seven Samoans with triplicated alpha-globin loci, while digestion with Bam HI produced an abnormal elongated 18.2 kb fragment carrying alpha-globin genes in addition to the normal 14.5 kb fragment. None of the Polynesian Samoans had alpha thal2 or alpha thal1. Only two of the Malaysians had triplicated alpha-globin loci.
The level of serum alpha-fetoprotein (AFP) was estimated by radioimmunoassay in 153 normal healthy Malysians of different ethnic groups. The mean level was 7.5 In1/ml (SD 2.28InU/ml). Among 330 patients with malignant tumors, 11 had increased levels of AFP. The only patient who had hepatoma had a very high level of serum AFP. High levels were also found in three of four patients with dysgerminoma of the ovary, in the only two patients with carcinoma of the testis, and in one patient with secondary carcinoma of the humerus of unknown origin. Lower, but significantly increased levels were observed in one patient (of 48) with breast carcinoma, one patient (of 8) with basal cell carcinoma of the nose, one patient (0f 27) with carcinoma of the lung, and one patient (of 59) with nasopharynegeal carcinoma.
A study of 23 patients with Hb H disease and their 82 relatives in 17 families showed that 2 types of this condition exist. One is associated with the presence of a small slow-moving component, which we tentatively called the X component and which was invariably present in one parent. Some siblings also had it. The other type was not associated with this component. Two patients without X component had a newborn with Bart’s haemoglobin without X component. None of the parents of 20 newborns with Hb Bart’s without the X component had the X component. It was present in only one parent of each of 2 newborns with Hb Bart’s and the X component. They are thought to represent Hb H disease in the newborn period. We suggest that at least 3 abnormal genes may lead to Hb H disease, which results when 2 of the 3 combine. Severity of clinical and haematological symptoms depends upon which abnormal gene is present and which 2 are involved in any particular combination.
Key Words: a-Thalassaemia; Haemoglobin Bart’s; Haemoglobin H disease; Haemoglobinopathies
A survey of abnormal hemoglobins, G6PD deficiency and hereditary ovalocytosis was carried out among the Dayaks of Sarawak. The only abnormal hemoglobin found was Hb Co Sp, which occurred in 0.35% of the Land Dayaks and 0.83% of the Sea Dayaks. G6PD deficiency occurred in 5.3% of the male Land Dayaks and 5.0% of the male Sea Dayaks; no electrophoretic variant of G6PD was found in any of the 285 Land Dayaks and 240 Sea Dayaks examined. Hereditary ovalocytosis was found in 12.7% of the Land Dayaks and 9.0% of the Sea Dayaks.
944 adenosine deaminase phenotypings of Malay, Chinese, and Indian blood donors and newborns at Kuala Lumpur, Malaysia, yielded ADA1 gene frequency estimates of 0.885 for the Malays, 0.939 for the Chinese, and 0.853 for the Indians.
A total of 1008 healthy unrelated young adult male police and military recruits, 317 from Brunei, 398 from Sabah and 293 from Sarawak, were examined for G-6-PD deficiency. The frequency in the 317 Brunei recruits, who were all of Malay origin, was 6.3 %. In Sabah the frequencies for the four main ethnic groups were 12.1 % in 165 Kadazans, 4.1% in 73 Malays, 3.4 % in 68 Bajaus and 24.2 % in 33 Muruts. In Sarawak the frequency was 11.6 % in 95 recruits of Malay origin. Three among 56 Ibans and one among 80 Sea Dayaks were found to be enzyme-deficient, but the numbers examined of these groups were too small for estimation of the frequency. The overall frequency for the Malay group in Brunei, Sabah and Sarawak was 7.0% in 485 persons examined.