Prenatal exclusion of Ehlers-Danlos syndrome type VI by mutational analysis.

We have performed the first prenatal assessment of clinical phenotype in a family affected by Ehlers-Danlos syndrome type VI (EDS VI), an inherited collagen disorder, by screening the fetal DNA for mutations in the lysyl hydroxylase (LH) gene. We have previously reported that the affected child in this family is compound heterozygous for mutations in the LH gene. One allele has a paternally inherited C1557 to G change that codes for a premature stop codon (Y511X) in exon 14 and the other allele has a deletion of exon 5 that results from a maternally inherited mutation in the consensus donor splice site of intron 5. To perform the prenatal diagnosis, we sequenced genomic DNA isolated from cultured chorionic villus cells at 10 weeks of gestation. One allele had the maternally inherited gt --> at splice-site mutation in exon 5, and the other paternally inherited allele was normal. As EDS VI is a recessive disorder, we predicted that although a carrier, the baby should be unaffected. This conclusion, which was supported by a normal level of LH activity in the chorionic villus cells, was confirmed by the birth of a healthy unaffected baby.