DNA-based prenatal diagnosis in a Chinese family with xeroderma pigmentosum group A.
BACKGROUND
Xeroderma pigmentosum (XP) is a group of autosomal recessive diseases characterized by hypersensitivity to ultraviolet rays. Among its eight complementation groups, XP group A (XPA) is the most severe type. The XPAC gene has been identified as the defective gene in XPA patients.


OBJECTIVE
To examine genomic DNA from a Chinese family with XPA, to determine the XPAC mutation and, after genetic counselling, to undertake DNA-based prenatal diagnosis in a subsequent pregnancy.


METHODS
Fetal DNA was extracted from amniotic fluid and used to amplify exon 5 of XPAC containing the potential mutation. Direct sequencing and restriction endonuclease digestion were used for prenatal diagnosis.


RESULTS
We identified a homozygous nonsense XPAC mutation of 631C-->T, which results in an R211X mutation in XPA protein, in the proband. Both her parents are heterozygous. Prenatal diagnosis demonstrated a heterozygous sequence predicting an unaffected child, and a healthy girl was born.


CONCLUSIONS
These data provide the first example of a DNA-based prenatal test for genodermatosis in China.
Yang
Y
Y
Department of Dermatology, Peking University First Hospital, Beijing, China. yongyang81@yahoo.com.cn
Ding
B
B
Wang
K
K
Bu
D
D
Tu
P
P
Zhu
X
X
D002675:Child, Preschool; D002681:China; D018389:Codon, Nonsense; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D010375:Pedigree; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D012871:Skin Diseases / Q000175:diagnosis* / Q000235:genetics; D014983:Xeroderma Pigmentosum / Q000175:diagnosis* / Q000235:genetics; D051760:Xeroderma Pigmentosum Group A Protein
D018389:Codon, Nonsense; D004268:DNA-Binding Proteins; C497314:XPA protein, human; D051760:Xeroderma Pigmentosum Group A Protein