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| MUTATION | |
Codons 57/58 (+C); AAC·CCT(Asn·Pro)->AAC·C·CCT | |
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| AMINO ACID REPLACEMENT | |
None | |
| TYPE OF BETA-THAL | |
beta° | |
| MECHANISM | |
The introduction of a C between codons 57 and 58 causes a frameshift with a stop codon at codon 59 (TAA) resulting in a premature termination of translation | |
| IDENTIFICATION | |
Amplification of the beta-globin gene; automated sequencing; dot-blot analysis with allele specific probes | |
| HEMATOLOGY IN HETEROZYGOTE(S) | |
The mother is heterozygous: Hb 10.0 g/dl; MCV 60 fl; MCH 19.3 pg; Hb A2 5.0%; one sister is also a heterozygote | |
| HEMATOLOGY IN HOMOZYGOTE(S) | |
Not reported | |
| OCCURRENCE | |
Found in a Sikh family living in the United Arab Emirates | |
| HAPLOTYPE | |
Not reported | |
| FOUND IN COMBINATION WITH ABNORMAL HB(S) | |
None | |
| FOUND IN COMBINATION WITH BETA-THAL ALLELE(S) | |
The proband was a compound heterozygote for this mutation and the frameshift at codons 47/48 (+ATCT); severe thalassemia major with transfusion dependency | |
| OTHER INFORMATION | |
At the age of 13 months, the proband received a successful bone marrow transplant from his heterozygous sister [with the codon 57/58 (+C) frameshift]; his latest hematology: Hb 10.2-10.8 g/dl; MCV ~60 fl; MCH ~18.5 pg; Hb A2 5.0%; Hb F 1.0% | |