Premium
False non‐paternity in a family for prenatal diagnosis of β‐thalassaemia
Author(s) -
Chan Vivian,
Chan T. P. T.,
Lau K.,
Todd D.,
Chan T. K.
Publication year - 1993
Publication title -
prenatal diagnosis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.956
H-Index - 97
eISSN - 1097-0223
pISSN - 0197-3851
DOI - 10.1002/pd.1970131012
Subject(s) - genetics , frameshift mutation , nonsense mutation , prenatal diagnosis , mutation , biology , allele , stop codon , gene , pregnancy , fetus , missense mutation
Initial screening for the common β‐thalassaemia mutations with allele‐specific oligonucleo‐tide probes in an at‐risk family suggested non‐paternity. Subsequent DNA fingerprinting of the members proved otherwise. The mother had a codon 41/42 frameshift mutation and the father's defect, determined by direct sequencing of PCR‐amplified β gene, was a codon 43 nonsense mutation. In the affected children, the close proximity of these two defects resulted in the absence of a hybridization signal to the normal probe in that region and a wrong assumption of homozygosity for the codon 41/42 mutation. The non‐reactivity of the father's amplified DNA to the codon 41/42 thalassaemic probe accounted for the initial wrong conclusion of non‐paternity. Since prior screening for β‐thalassaemia mutations is done in all prenatal diagnosis programmes and concomitant inheritance of these two defects is relatively common in the Chinese, this ‘artefact’ of false non‐paternity is worth noting.