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. Author manuscript; available in PMC: 2011 Jun 1.
Published in final edited form as: Clin Genet. 2010 Feb 4;77(6):563–571. doi: 10.1111/j.1399-0004.2009.01344.x

Table 1.

Reported 'DFNB2'-causing mutations in the MYO7A gene

Family Mutation Domain Type Age of onset Frequency loss Vestibular dysfunction RP References
1 Chinese (DFNB.01) p.R244Pa Motor DFNB2? Congenital All frequencies Some affected family members (CT) No (ERG) 5
1 Chinese (DFNB.05) IVS3nt-2A>Ga,b
p.V1199insT[FS]a,b 		Multiple domains DFNB2? Congenital All frequencies All affected family members (CT) No (ERG) 5
1 Tunisian p.M599Ic Motor USH1B? Birth up to 16 years All frequencies Some affected family members (CT) Yes (FU) 4
1 Pakistani (PKDF034) p.E1716del Unknown DFNB2 Congenital All frequencies No (CT) No (ERG; FU) 13
1 Iranian (L-1419) p.R395H Motor DFNB2 Seven months up to 7 years All frequencies No (CT) No (FU) This study

CT, caloric tests; ERG, electroretinograms; FU, funduscopy; RP, retinitis pigmentosa.

a

These families were reported to have the DFNB2 phenotype (9). However, they both exhibit profound hearing loss across all frequencies and vestibular dysfunction is present in atleast some affected family members. Early onset RP was ruled out by ERG in affected family members (between 25 and 33 years of age) but late-onset RP has not been excluded. Independent studies have speculated that these families are more likely to have the USH1B phenotype (13, 27).

b

Compound heterozygous.

c

This mutation was originally associated with the DFNB2 phenotype. However, affected members of the Tunisian family were subsequently shown to develop RP as early as 25 years of age (USH1B) (25).