Frequency of delta+ 27-thalassaemia in Sardinians.
To determine the incidence of delta+ 27 thalassaemia in Northern Sardinia we examined blood samples from 750 Sardinian schoolboys by PCR-based molecular analysis. The incidence of delta+ 27 mutation was 1.2% in this study, i.e. twice as high as previously described on the basis of phenotypical studies; the frequency of the beta-thalassaemia is 10.5% and their interaction has been calculated at 0.0003. The majority of delta+ 27 carriers are characterized by a HbA2 level lower than 1.9% and the mean HbA2 level is significantly lower than in normal subjects. All compound heterozygotes for delta+ 27 and beta-thalassaemia show a silent beta-thalassaemic phenotype related to normalization of their HbA2 levels. This study suggests that delta+ 27 thalassaemia should be borne in mind in counselling at-risk couples in which one member has the typical high HbA2 beta-thal trait while the other shows normal or borderline HbA2 level. In these subjects, PCR-based ECO O 109 I digestion of the delta globin gene allows rapid detection of the delta+ 27 mutation.
Guiso
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L
Istituto CNR per lo Studio della Patologia del Sangue e degli Organi Emopoietici, Università di Sassari, Italy.
Frogheri
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L
Pistidda
P
P
Angioni
L
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Dore
F
F
Pardini
S
S
Longinotti
M
M
D000293:Adolescent; D004252:DNA Mutational Analysis; D004913:Erythrocytes, Abnormal / Q000502:physiology; D005914:Globins / Q000737:chemistry / Q000235:genetics; D006239:Haplotypes / Q000235:genetics; D006443:Hemoglobin A2 / Q000235:genetics / Q000378:metabolism; D006579:Heterozygote; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D017354:Point Mutation / Q000235:genetics / Q000502:physiology; D016133:Polymerase Chain Reaction; D013789:Thalassemia / Q000097:blood / Q000453:epidemiology* / Q000235:genetics; D017085:alpha-Thalassemia / Q000097:blood / Q000503:physiopathology; D017086:beta-Thalassemia / Q000097:blood / Q000235:genetics / Q000517:prevention & control
D005914:Globins; D006443:Hemoglobin A2