Table 1.
| a. Mutations in human AQP0 and characteristics of the resulting lens cataract | |||||
|---|---|---|---|---|---|
| Families with Congenital Lens Cataract |
Mutation in AQP0 gene |
Specificity of mutation in AQP0 protein |
Location of the mutation in AQP0 protein |
Phenotype | Reference |
| Family A from southern England |
Point mutation C to G transversion (exon 2) |
Point mutation T138 to R (AQP0 - 263 amino acids (aa)) |
Transmembrane H4 | Polymorphic cataract. Congenital, isolated, progressive, bilateral, punctate lens opacities limited to mid and peripheral lamellae or asymmetric anterior and posterior polar opacification or cortical cataract |
Berry et al., 2000 |
| Family B from southeastern England |
Point mutation A to G transition (exon 2) |
Point mutation E134 to G (AQP0 - 263 aa) |
Transmembrane H4 | Isolated, non-progressive, congenital lamellar and sutural opacification |
Berry et al., 2000 |
|
Family ADC2, European descent |
One base pair deletion (exon 4) |
Frameshift (G213Vfs*45) at codon 213; #213 to 257 aa in frameshift at C-terminus (Shortened AQP0 =257 aa) |
Transmembrane H6 and cytoplasmic C-terminus |
Congenital bilateral cataract; Embryonic nuclear opacities |
Geyer et al., 2006 |
|
Chinese Family 1 |
Point mutation C to T transition (exon 1) |
Point mutation R33 to C (AQP0 263 aa) |
Extracellular Loop A |
Congenital total cataract; bilateral, complete opacification of the fetal nucleus and the cortex |
Gu et al., 2007 |
|
Chinese Family 2 |
Point mutation G to A transition (exon 4) |
Point mutation R233 to K (AQP0 263 aa) |
cytoplasmic C-terminal |
Dominant binocular polymorphic cataract | Lin et al., 2007 |
|
Chinese Family 3 |
splice-site mutation (c.607-1 G to A transition) |
Premature stop codon, (AQP0 205 aa) |
Loss of Transmembrane H6 and cytoplasmic C-terminal |
congenital total cataract, snaillike” phenotype | Jiang et al., 2009 |
|
Chinese Family 4 |
Point mutation c.319- G to A transition |
Point mutation V107 to I (AQP0 - 263 aa) |
Mutation in Extracellular Loop C |
Y-suture and nuclear pulverulent opacification; complete opacification in the fetal nuclear region |
Wang et al., 2010 |
|
Chinese Family 5 |
Point mutation C.559 C to T transition |
Point mutation R187 to C (AQP0 - 263 aa). |
Helix E | Bilateral congenital nuclear cataract |
Wang et al., 2011 |
|
Chinese Family 6 |
Point mutation (c. 530 A to G transition) |
Point mutation Y177 to C (AQP0 - 263 aa) |
Transmembrane H5 | Dominant congenital nuclear cataract |
Yang et al., 2011 |
|
Chinese Family 7 |
Point mutation c.2 T to C transition |
Point mutation at start codon |
Mutation affects the initiation codon, ATG, which may result in no protein production or activation of a new translation initiation site |
Cerulean cataract with different morphology (lamellar, punctuate, and/or Y-sutural) in different patients |
Xiao et al., 2011 |
| South Indian family 1 |
Point mutation c.494 G to A transition |
Point mutation G165 to D (AQP0 - 263 aa) |
Transmembrane H5 | Congenital lamellar cataract | Senthil Kumar et al., 2013 |
| b. Mutations in mouse AQP0 and characteristics of the resulting lens cataract | |||||
|---|---|---|---|---|---|
| Mouse with Congenital Lens Cataract |
AQP0 gene Mutation |
Specificity of mutation in AQP0 protein |
Location of the mutation in AQP0 protein domain* |
Phenotype | Reference |
|
CatFr (Fraser) |
Insertion transposon in intron 3/ exon 4 junction |
Replacement amino acid (aa) #203 to 263 at C-terminus by transposon sequence (E Tn) (AQP0 - 261 aa) |
Transmembrane H6 and cytoplasmic C-terminus |
Progressive Lens fiber degeneration and cataractogenesis |
Shiels and Bassnett, 1996 |
|
Lop (Lens opacity) |
Point mutation G to C transversion (exon 1) |
Point mutation aa #51 A to P (AQP0 - 263 aa) |
Transmembrane H2 | Progressive lens fiber cell degeneration and cataractogenesis |
Shiels and Bassnett, 1996 |
|
Hfi (Hydropic lens) |
Deletion of 76 base pair at junction exon 2/ intron 2 |
Deletion 55 aa #128 to #175 (AQP0 - 208 aa) |
Transmembrane H4 and H5, extracellular loop C and intracellular loop D |
Heterozygotes with hydropic lens fibers and homozygotes with total lens cataract |
Sidjanin et al., 2001 |
|
CatTohm (Tohoku) |
Deletion of 12 base pair (exon 1) |
Deletion aa #46 to 49 (AQP0 259 aa) |
Transmembrane H2 | Severe lens fiber degeneration and cataractogenesis. Dominant cataract |
Okamura et al., 2003 |
*
AQP0 protein domains correspond to those indicated Fig. 1A, B