"we report compound heterozygous frameshift and splice site mutations in P4HA1 that impair but not abolish C-P4H alpha(I) activity. The maternal P4HA1 exon 12 splice donor site mutation causes an internally deleted C-P4H alpha(I) predicted to completely lack catalytic activity. two nucleic acid insertion in exon 9 results in a premature stop in the exon 9 P4HA1 splice form."xsd:string