Haplotype Assay
STRs segregation study resulted informative, as 4/5 of the analyzedloci were heterozygous. Conformed haplotypes are depicted in
figure 1A. Haplotype analysis not only allowed us to exclude CVS´s
maternal blood contamination, as the CVS presented only 1 maternal
X-chromosome, but also predicted a female gender given that two
X-chromosomes were detected. Noteworthy, a 1-step retraction of STR49
was also observed in the fetus. On the other hand, we could bring out
the previously reported deletion in III4 by the absence of amplification
for STR45 and STR49. Granted that II1, II3 and III1 resulted
heterozygous for STR49, we could predict that they didn´t carry III4’s
deletion, however, they share a fraction of the at-risk haplotype
(STRDYSII and STR44). Moreover, sisters II1 and II3 showed a different
paternal haplotype. Finally, another important result was the
observation of a recombinant X-chromosome, between STR44 and STR45, in
III4.