Usher Syndrome
Usher syndrome is characterised by hearing impairment and retinitis pigmentosa. Usher syndrome can be classified into 3 different types on the basis of clinical findings.
Clinical classification

Type

Hearing impairment

Vestibular responses

Onset of retinitis pigmentosa

Type I

Profound hearing loss
Congenital

Absent

Onset in first decade

Type II

Sloping audiogram
Congenital

Normal

Onset in first or second decade

Type III

Progressive hearing loss

Variable

Variable

 

 

 

 


Molecular classification

Locus

Location

Gene

References

OMIM entry

USH1A

(14q32 )

non existent

Kaplan et al., 1992 ; Gerber et al., 2006

276900

USH1B

11q13.5

MYO7A

Weil et al.,1995

276903

USH1C

11p15.1

USH1C

Smith et al., 1992 ; Verpy et al., 2000 ; Bitner-Glindzicz et al., 2000

276904

USH1D

10q22.1

CDH23

Wayne et al., 1996 ; Bork et al., 2001 ; Bolz et al., 2001

601067

USH1E

 21q21

unknown

Chaib et al., 1997

602097

USH1F

10q21-22

PCDH15

Ahmed et al., 2001 ; Alagramam et al., 2001

602083

USH1G

17q24-25

SANS

Mustapha et al., 2002 ; Weil et al., 2003

606943

USH1H

15q22-23

unknown

Ahmed et al., 2009

612632

USH1J (see note A) 15q23-q25.1 CIB2  (refuted, see note A) Riazuddin et al., 2012 Booth et al., 2017 614869
USH1K 10p11.21-q21.1 unknown Jaworek et al., 2012 614990

USH2A

1q41

USH2A

Kimberling et al., 1990 ; Eudy et al., 1998

276901

USH2B

3p23-24.2.

unknown

Hmani et al., 1999

 

USH2C

5q14.3-q21.3

VLGR1

Pieke-Dahl et al., 2000 ;  Weston et al., 2004

605472

USH2D

9q32

WHRN

Ebermann et al., 2007

611383

USH3

3q21-q25

CLRN1

Sankila et al., 1995 ; Joensuu et al., 2001

276902
606397

USH3B 5q31.3 HARS Puffenberger et al., 2012 614504

Modifier Gene (see note B)

10q24.31 PDZD7 Ebermann et al., 2010


 

 

 


 

Note A: CIB2 cases autosomal recessive non-syndromic hearing loss; its role in Usher syndrome has been refuted, see Booth et al., 2017
Note B: PDZD7 causes autosomal recessive non-syndromic hearing loss; its role in Usher syndrome has been called in to question see Booth et al., 2015