Microsatellite mutation in the maternally/paternally transmitted D18S51 locus: two cases of allele mismatch in the child.
BACKGROUND
We investigated 2 cases of paternity dispute with 17 autosomal short tandem repeats (STR), that indicated a mismatch to the maternally and paternally inherited allele at D18S51 locus in children under inquiry.


METHODS
17 autosomal and Y STR loci were analyzed using AmpFlSTR Identifiler, PowerPlex 16, AmpFlSTR(R)Y-filertrade mark kits. The mitochondrial DNA hypervariable regions HV1 and HV2 and 6 STR markers on X chromosome were amplified and sequenced.


RESULTS
In case M1, allelic representation in the mother, questioned child and suspected father was 14/19, 12/20 and 12/14 respectively. A complete match with the mother at 6 X STR loci and mitochondrial hypervariable regions was observed. In case F1, allelic representation was 13/14, 14/20 and 16/18 respectively. A complete match with the father at 17 Y chromosome STR loci was observed. D18S51 sequence analysis indicates the expansion of 1 repeat in M1 and 2 repeats in F1 leading to allele mismatch in the child.


CONCLUSIONS
The probability of maternity and paternity were 0.999999 and 0.999999 respectively. This is the first report of a maternally/paternally transmitted D18S51 mutations in the paternity DNA testing. These results conclusively determined that the mother and suspected father are the biological parents of the questioned children in both the cases.
Narkuti
Venkanna
V
Andhra Pradesh Forensic Science Laboratory, Red Hills, Hyderabad, A.P-500004, India.
Vellanki
Ravi N
RN
Gandhi
K P C
KP
Doddapaneni
Kiran K
KK
Yelavarthi
Pramila D
PD
Mangamoori
Lakshmi N
LN
D000328:Adult; D041321:Chromosomes, Human, X / Q000235:genetics; D041322:Chromosomes, Human, Y / Q000235:genetics; D022801:Complementarity Determining Regions / Q000235:genetics; D016172:DNA Fingerprinting; D004272:DNA, Mitochondrial / Q000235:genetics; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics*; D009154:Mutation / Q000235:genetics* / Q000502:physiology*; D009841:Oligonucleotides / Q000235:genetics; D010334:Paternity; D020080:Tandem Repeat Sequences / Q000235:genetics*
D022801:Complementarity Determining Regions; D004272:DNA, Mitochondrial; D009841:Oligonucleotides