S. Desai et al., IS CELLULOSE-ACETATE ELECTROPHORESIS A SUITABLE TECHNIQUE FOR DETECTION OF HB BARTS AT BIRTH, Human heredity, 47(4), 1997, pp. 181-184
Symptomatic alpha-thalassemia (alpha-thal) as found in South-East Asia
is uncommon in India. However, the presence of Hb Bart's in cord bloo
d samples has been reported from different parts of India and the prev
alence of alpha-thal has ranged from 0.5 to 18% by different electroph
oretic techniques. The methodology utilised has ranged from paper elec
trophoresis to isoelectric focusing (IEF). We screened 798 cord bloods
for the presence of Hb Bart's by cellulose acetate electrophoresis an
d found a prevalence rate of alpha-thal of 15.3% in a heterogenous pop
ulation in Bombay. A comparison of four different electrophoretic tech
niques for detection of Hb Bart's in 138 neonates showed that cellulos
e acetate and starch gel electrophoresis were by and large comparable
and only a little less sensitive than IEF. Paper electrophoresis used
at many centers in India was most insensitive. As cr-genotyping is not
possible at most centers in the country, it is suggested that a simpl
e cellulose acetate electrophoresis would be the method of choice for
screening neonates for alpha-thal in India. As a part of our follow-up
study, alpha-genotyping was done by Southern blot hybridization in 24
cases who had shown variable levels of Hb Bart's at birth. The rightw
ard deletion (-alpha(3.7)/) either in a heterozygous or homozygous con
dition was the only gene defect encountered in this preliminary study.
However, 7 of 24 cases (29.17%) showed no correlation between Hb Bart
's level and alpha-genotypes.