{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,5]],"date-time":"2025-10-05T18:41:21Z","timestamp":1759689681257,"version":"build-2065373602"},"reference-count":9,"publisher":"BMJ","issue":"3","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J Med Genet"],"published-print":{"date-parts":[[1988,3]]},"abstract":"<jats:p>The clinical and haematological phenotype as well as chain synthesis data were studied in 35 doubly heterozygous patients with either normal Hb A2 and Hb F, type 2 beta thalassaemia and beta (high A2) thalassaemia (26 patients), or type 2 and other rare beta or delta beta variants (nine patients). Patients doubly heterozygous for type 2 and beta zero or delta beta zero thalassaemia variants had no detectable Hb A, indicating that the type 2 normal A2 beta thalassaemia is primarily the result of a beta zero gene. The clinical phenotype varied from severe thalassaemia major to mild thalassaemia intermedia, and was mainly related to the thalassaemia variant with which the type 2 normal A2 beta thalassaemia was combined, and the proportion of Hb A produced in beta + thalassaemia patients. Haematological and chain synthesis data were similar in heterozygotes with type 2 and beta zero or beta + (high A2) thalassaemia. Hb A2 levels were within the normal range (2.3 to 3.6%) though absolute values (Hb A2 per RBC) ranged from low normal (0.5 pg\/RBC) to increased levels (1.0 pg\/RBC.) The variation of Hb A2, as well as the presence of Hb A2 in a type 2\/delta beta high F patient and the complete absence of HbA2 in a homozygous type 2 patient, indicate that there are at least two genotypes of type 2, one beta zero and the other delta beta zero. This has been recently proven by gene mapping studies. For clinicians, routine haematological and family studies are sufficient for the proper treatment and prevention of doubly heterozygous type 2 patients.<\/jats:p>","DOI":"10.1136\/jmg.25.3.195","type":"journal-article","created":{"date-parts":[[2008,11,10]],"date-time":"2008-11-10T15:11:11Z","timestamp":1226329871000},"page":"195-199","source":"Crossref","is-referenced-by-count":4,"title":["Clinical, haematological, and genetic studies of type 2 normal Hb A2 beta thalassaemia."],"prefix":"10.1136","volume":"25","author":[{"given":"A","family":"Metaxotou-Mavromati","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"C","family":"Kattamis","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"L","family":"Matathia","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M","family":"Tzetis","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"E","family":"Kanavakis","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[1988,3,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1111\/j.1365-2141.1979.tb03703.x","article-title":"The heterogeneity of normal Hb A2-I3-thalassaemia in Greece","volume":"42","author":"Kattamis, C.; Metaxotou-Mavromati, A.; Wood, W.; Nash, J.; Weatherall, D.","year":"1979","unstructured":"Kattamis C, Metaxotou-Mavromati A, Wood W, Nash J, Weatherall D. The heterogeneity of normal Hb A2-I3-thalassaemia in Greece. Br J Haematol 1979;42:109-23.","journal-title":"Br J Haematol"},{"key":"ref_2","first-page":"257","article-title":"The pattern of disordered haemoglobin sythesis in homozygous and heterozygous 1-thalassaemia","volume":"16","author":"Weatherall, D.; Clegg, J.; Wasi, Na-Nakorn S.; P.","year":"1966","unstructured":"Weatherall D, Clegg J, Na-Nakorn S. Wasi P. The pattern of disordered haemoglobin sythesis in homozygous and heterozygous 1-thalassaemia. Br J Haematol 1966;16:257-67.","journal-title":"Br J Haematol"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1007\/978-3-642-67488-4_12","article-title":"Screening for haemoglobinopathies (thalassaemias and other abnormal haemoglobins)","volume-title":"Neonatal screening for inborn errors of metabolism","author":"Kattamis, C.","year":"1980","unstructured":"Kattamis C. Screening for haemoglobinopathies (thalassaemias and other abnormal haemoglobins). In: Bickel H, Guthrie R, Hammersen G, eds. Neonatal screening for inborn errors of metabolism. Berlin: Springer-Verlag, 1980:133-47."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"738","DOI":"10.1136\/jcp.25.8.738","article-title":"Reliable routine estimation of small amounts of foetal haemoglobin by alkali denaturation","volume":"25","author":"Pembrey, M.; McWade, P.; Weatherall, D.","year":"1972","unstructured":"Pembrey M, McWade P, Weatherall D. Reliable routine estimation of small amounts of foetal haemoglobin by alkali denaturation. J Clin Pathol 1972;25:738-40.","journal-title":"J Clin Pathol"},{"key":"ref_5","first-page":"91","article-title":"Abnormal human hemoglobins. Separation and characterization of the a and P8 chains by chromatography and the determination of two new variants Hb","volume":"19","author":"Clegg, J.; Naughton, M.; Weatherall, D.","year":"1966","unstructured":"Clegg J, Naughton M, Weatherall D. Abnormal human hemoglobins. Separation and characterization of the a and P8 chains by chromatography and the determination of two new variants Hb Chesapeake and Hb J (Bangkok). J Mol Biol 1966;19:91-9.","journal-title":"Chesapeake and Hb J (Bangkok). J Mol Biol"},{"key":"ref_6","first-page":"135","article-title":"The clinical phenotype of P and 6bI thalassemias in Greece","volume":"193","author":"Kattamis, C.; Metaxotou-Mavromati, A.; Ladis, V.; Tsiarta, H.; Laskari, S.; Kanavakis, E.","year":"1982","unstructured":"Kattamis C, Metaxotou-Mavromati A, Ladis V, Tsiarta H, Laskari S, Kanavakis E. The clinical phenotype of P and 6bI thalassemias in Greece. Eur J Pediatr 1982;193:135-8.","journal-title":"Eur J Pediatr"},{"key":"ref_7","first-page":"29","article-title":"Prevalence of,0 and P thalassemia genes in Greek children with homozygous 3-thalassemia","volume":"2","author":"Kattamis, C.; Karambula, K.; Metaxotou-Mavromati, A.; Ladis, V.; Constantopoulos, A.","year":"1978","unstructured":"Kattamis C, Karambula K, Metaxotou-Mavromati A, Ladis V, Constantopoulos A. Prevalence of,0 and P thalassemia genes in Greek children with homozygous 3-thalassemia. Hemoglobin 1978;2:29-46."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1111\/j.1749-6632.1985.tb17171.x","article-title":"A novel deletion in the 3- globin gene complex","volume":"445","author":"Wainscoat, J.; Thein, S.; Wood, W.","year":"1985","unstructured":"Wainscoat J, Thein S, Wood W, et al. A novel deletion in the 3- globin gene complex. Ann NY Acad Sci 1985;445:20-7.","journal-title":"Ann NY Acad Sci"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1111\/j.1365-2141.1982.tb07289.x","article-title":"Globin gene mapping in normal Hb A2 types of 3-thalassaemia","volume":"51","author":"Kanavakis, E.; Metaxotou-Mavromati, A.; Kattamis, C.; Aksoy, M.; Weatherall, D.; Wood, W.","year":"1982","unstructured":"Kanavakis E, Metaxotou-Mavromati A, Kattamis C, Aksoy M, Weatherall D, Wood W. Globin gene mapping in normal Hb A2 types of 3-thalassaemia. Br J Haematol 1982;51:59-64.","journal-title":"Br J Haematol"}],"container-title":["Journal of Medical Genetics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/jmg.25.3.195","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,5]],"date-time":"2025-10-05T18:25:45Z","timestamp":1759688745000},"score":1,"resource":{"primary":{"URL":"https:\/\/jmg.bmj.com\/lookup\/doi\/10.1136\/jmg.25.3.195"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1988,3]]},"references-count":9,"journal-issue":{"issue":"3","published-online":{"date-parts":[[1988,3,1]]},"published-print":{"date-parts":[[1988,3]]}},"alternative-id":["10.1136\/jmg.25.3.195"],"URL":"https:\/\/doi.org\/10.1136\/jmg.25.3.195","relation":{},"ISSN":["0022-2593","1468-6244"],"issn-type":[{"type":"print","value":"0022-2593"},{"type":"electronic","value":"1468-6244"}],"subject":[],"published":{"date-parts":[[1988,3]]}}}