NLRP7 mutation analysis in sporadic hydatidiform moles in Tunisian patients: NLRP7 and sporadic mole.

CONTEXT: Hydatidiform mole, an aberrant human pregnancy, is commonly a nonrecurrent disease. Recently, a rare autosomal recessive form of familial and/or recurrent molar pregnancies was associated with mutations in the NLRP7 gene.

OBJECTIVE

To investigate whether NLRP7 mutations exist in Tunisian women with sporadic hydatidiform moles.

DESIGN

Genomic DNA from 38 unrelated Tunisian patients with sporadic hydatidiform moles were screened by sequencing all NLRP7 exons. A high-resolution melting curve analysis was performed on 170 DNA controls to analyze new sequence variants.

RESULTS

More than 13% of these patients were heterozygous for NLRP7 mutations. We found 2 novel missense mutations in the heterozygous state, c.544G>A (p.Val182Met) in 1 patient and c.1480G>A (p.Ala494Thr) in 2 patients, and 2 already reported mutations, c.1532A>G (p.Lys511Arg) and c.2156C>T (p.Ala719Val), in 2 patients. None of these mutations were identified in 170 controls except for 1 woman who was heterozygous for p.Val182Met.

CONCLUSION

As homozygous NLRP7 mutations are associated with recurrent hydatidiform mole or conception loss, the heterozygous state could represent a risk factor for nonrecurrent mole.