An Ehlers-Danlos syndrome type VIA patient with cystic malformations of the meninges.

We have characterized a patient with the phenotype of Ehlers-Danlos syndrome type VIA (EDS VIA: kyphoscoliotic form), accompanied by the unique feature of cystic malformations of the meninges, to be homozygous for a large duplication of 8.9 kb in the lysyl hydroxylase 1 (LH1) gene that is the cause of severely decreased levels of LH activity in her skin fibroblasts. Electrophoresis of full length cDNA for LH1, prepared from the patient's fibroblasts and amplified by PCR, showed an abnormally large DNA fragment indicative of a duplication mutation; this mutation was confirmed in genomic DNA by PCR using duplication-specific primers and sequence analysis of the duplication junction. The homozygosity of this mutation was confirmed by analysis of DNA from the unaffected parents which showed them to be carriers of this duplication. This seven exon duplication is the most common mutation in the LH1 gene in patients with EDS VIA and occurs via a homologous recombination of Alu sequences in introns 9 and 16. Using the data from this study and other recent reports, we have updated the allele frequency for this mutation, based on 19 duplicated alleles out of a total of 104 genetically independent alleles from 53 EDS VIA families, to be 18.3%.