Table 1. Description of families, phenotype and GJB2 mutations.

Results are tabulated for 8 of 84 families and 4 of 86 sporadic individuals positive for mutations in GJB2.

ID	Hearing Loss, PTA500-4000*, dB HL	Mutation	Comment
Familial Cases
HLRB1	Moderate to severe 54,65, 71,103	p.W77X/p.W77X	4 affected individuals in 3 loops (1 affected individual has a profound HL)
HLRB8	Moderate to severe 70, 78, 78	p.W24X/p.W77X	6 affected individuals in 2 loops
HLAI-02	Severe and profound 81, 86, 88, 98, 103, 104	p.W24X/p.W24X	8 affected individuals in 5 loops (3 individuals have profound deafness)
HLAI-12	Moderate to severe 59, 71, 90	p.W24X/p.W24X	3 affected individuals
HLAM09	Moderate to severe 61	p.W24X/p.W77X	3 affected individuals
HLGM25	Moderate to severe 70, 70, 94	p.W24X/p.W24X	5 affected individuals in 2 loops (1 affected individual has profound HL)
HLMS16**	Severe 74,79	p.W24X/p.W24X	2 affected individuals
HLMS34**	Severe 75, 78	p.W24X/p.W24X	2 affected individuals in 2 loops
Sporadic cases
HLMS11	Severe 84	p.W77X/p.W77X	NA
HLMS25	Severe 84	p.W24X/p.W24X	NA
SA15	Severe 89	p.W24X/p.W24X	NA
HLRB15#	Severe 82	p.W24X/p.W24X	NA

^*Pure-tone air conduction averages, db HL, for hearing thresholds at 500, 1000, 2000 and 4000 Hz (PTA^500-4000) of the better hearing ear is provided for all affected participants, except for those who refused the evaluation.

^**The only two families in the entire collection of 84 large pedigrees with inherited hearing loss which had 2 affected individuals in one or two consanguineous marriages. The other 82 families had multiple (3 or more) affected individuals in a single, or several marriage loops.

^#Although family HLRB15 had four affected individuals, sequencing revealed that only one participant had a homozygous mutation in GJB2. Therefore, the sample from this family is considered as a sporadic case. HL, Hearing Loss, NA, Not applicable.