Table 1.

Summary of Results for 642 DNA Samples Analyzed

Samples	642
No disease-causing mutation identified by DNA sequencing	401
No heterozygous polymorphism	76 → one whole gene deletion one exon 2 deletion one exon 3 duplication
With heterozygous polymorphisms	325
Disease-causing mutation identified by DNA sequencing	200; 156 unique
Nonsense mutations	107; 68 unique
Frameshift mutations	69; 66 unique
Splicing mutations	15; all unique
Missense mutations	9; 7 unique
Mutations of undetermined clinical significance	72
Missense (nonsynonymous)	36 (excluding 3 putative splice variants); 33 unique
Inframe residue insertion/deletion	3; all unique
Potential splice:
Intronic	17; 9 unique
Exonic, nonsynonymous	3; all unique
Exonic, synonymous	13; all unique