Limits...
Missense Mutations in CRYAB Are Liable for Recessive Congenital Cataracts.

Jiaox X, Khan SY, Irum B, Khan AO, Wang Q, Kabir F, Khan AA, Husnain T, Akram J, Riazuddin S, Hejtmancik JF, Riazuddin SA - PLoS ONE (2015)

Bottom Line: Subsequent interrogation of our entire cohort of familial cases identified a second familial case localized to chromosome 11q23 harboring a c.31C>T (p.R11C) mutation.Real-time PCR analysis identified the expression of Cryab in mouse lens as early as embryonic day 15 (E15) that increased significantly until postnatal day 6 (P6) with steady level of expression thereafter.Here, we report two novel missense mutations, p.R11C and p.R12C, in CRYAB associated with autosomal recessive congenital nuclear cataracts.

View Article: PubMed Central - PubMed

Affiliation: Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, United States of America.

ABSTRACT

Purpose: This study was initiated to identify causal mutations responsible for autosomal recessive congenital cataracts in consanguineous familial cases.

Methods: Affected individuals underwent a detailed ophthalmological and clinical examination, and slit-lamp photographs were ascertained for affected individuals who have not yet been operated for the removal of the cataractous lens. Blood samples were obtained, and genomic DNA was extracted from white blood cells. A genome-wide scan was completed with short tandem repeat (STR) markers, and the logarithm of odds (LOD) scores were calculated. Protein coding exons of CRYAB were sequenced, bi-directionally. Evolutionary conservation was investigated by aligning CRYAB orthologues, and the expression of Cryab in embryonic and postnatal mice lens was investigated with TaqMan probe.

Results: The clinical and ophthalmological examinations suggested that all affected individuals had nuclear cataracts. Genome-wide linkage analysis suggested a potential region on chromosome 11q23 harboring CRYAB. DNA sequencing identified a missense variation: c.34C>T (p.R12C) in CRYAB that segregated with the disease phenotype in the family. Subsequent interrogation of our entire cohort of familial cases identified a second familial case localized to chromosome 11q23 harboring a c.31C>T (p.R11C) mutation. In silico analyses suggested that the mutations identified in familial cases, p.R11C and p.R12C will not be tolerated by the three-dimensional structure of CRYAB. Real-time PCR analysis identified the expression of Cryab in mouse lens as early as embryonic day 15 (E15) that increased significantly until postnatal day 6 (P6) with steady level of expression thereafter.

Conclusion: Here, we report two novel missense mutations, p.R11C and p.R12C, in CRYAB associated with autosomal recessive congenital nuclear cataracts.

No MeSH data available.


Related in: MedlinePlus

Investigating the physical characteristics of wild-type and mutant CRYAB proteins.The polarity (A, D, G), the optimized matching hydrophobicity (B, E, H), and hydropathicity (C, F, I) plots of the wild-type and mutant CRYAB proteins. Both mutant proteins (R11C and R12C) revealed low polarity (compare A, with D and G), a higher hydrophobicity (compare B, with E and H), and higher hydropathicity (compare C, with F and I), respectively. The x-axis represents the position of amino acids. The y-axis represents the Polarity, hydrophobicity and Hydropathicity values in a default window size of 9. The arrows point to the difference in their respective polarities (1st arrow from the left), hydrophobicity (2nd arrow from the left) and hydropathicities (3rd arrow from the left).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4581838&req=5

pone.0137973.g005: Investigating the physical characteristics of wild-type and mutant CRYAB proteins.The polarity (A, D, G), the optimized matching hydrophobicity (B, E, H), and hydropathicity (C, F, I) plots of the wild-type and mutant CRYAB proteins. Both mutant proteins (R11C and R12C) revealed low polarity (compare A, with D and G), a higher hydrophobicity (compare B, with E and H), and higher hydropathicity (compare C, with F and I), respectively. The x-axis represents the position of amino acids. The y-axis represents the Polarity, hydrophobicity and Hydropathicity values in a default window size of 9. The arrows point to the difference in their respective polarities (1st arrow from the left), hydrophobicity (2nd arrow from the left) and hydropathicities (3rd arrow from the left).

Mentions: Subsequently, we examined the impact of these mutations on the physical characteristics of CRYAB. The ProtScale software predicted lower polarity, higher hydrophilicity and hydrophobicity of the mutant CRYAB compared to the wild type residues in protein secondary structure (Fig 5). In parallel, we used mCSM, a structure-based algorithm to validate the damaging nature of both missense variants identified in CRYAB. The analysis predicted the destabilizing nature of both variants (R11C and R12C) that would result in the disruption of the secondary structure of the protein (Table 2). Finally, we estimated the isoelectric point (pI) and computed molecular weight of the mutant CRYAB proteins. We found that both mutant CRYAB proteins had a lower pI (pI: 6.5) compared to the wild type CRYAB (pI: 6.76).


Missense Mutations in CRYAB Are Liable for Recessive Congenital Cataracts.

Jiaox X, Khan SY, Irum B, Khan AO, Wang Q, Kabir F, Khan AA, Husnain T, Akram J, Riazuddin S, Hejtmancik JF, Riazuddin SA - PLoS ONE (2015)

Investigating the physical characteristics of wild-type and mutant CRYAB proteins.The polarity (A, D, G), the optimized matching hydrophobicity (B, E, H), and hydropathicity (C, F, I) plots of the wild-type and mutant CRYAB proteins. Both mutant proteins (R11C and R12C) revealed low polarity (compare A, with D and G), a higher hydrophobicity (compare B, with E and H), and higher hydropathicity (compare C, with F and I), respectively. The x-axis represents the position of amino acids. The y-axis represents the Polarity, hydrophobicity and Hydropathicity values in a default window size of 9. The arrows point to the difference in their respective polarities (1st arrow from the left), hydrophobicity (2nd arrow from the left) and hydropathicities (3rd arrow from the left).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4581838&req=5

pone.0137973.g005: Investigating the physical characteristics of wild-type and mutant CRYAB proteins.The polarity (A, D, G), the optimized matching hydrophobicity (B, E, H), and hydropathicity (C, F, I) plots of the wild-type and mutant CRYAB proteins. Both mutant proteins (R11C and R12C) revealed low polarity (compare A, with D and G), a higher hydrophobicity (compare B, with E and H), and higher hydropathicity (compare C, with F and I), respectively. The x-axis represents the position of amino acids. The y-axis represents the Polarity, hydrophobicity and Hydropathicity values in a default window size of 9. The arrows point to the difference in their respective polarities (1st arrow from the left), hydrophobicity (2nd arrow from the left) and hydropathicities (3rd arrow from the left).
Mentions: Subsequently, we examined the impact of these mutations on the physical characteristics of CRYAB. The ProtScale software predicted lower polarity, higher hydrophilicity and hydrophobicity of the mutant CRYAB compared to the wild type residues in protein secondary structure (Fig 5). In parallel, we used mCSM, a structure-based algorithm to validate the damaging nature of both missense variants identified in CRYAB. The analysis predicted the destabilizing nature of both variants (R11C and R12C) that would result in the disruption of the secondary structure of the protein (Table 2). Finally, we estimated the isoelectric point (pI) and computed molecular weight of the mutant CRYAB proteins. We found that both mutant CRYAB proteins had a lower pI (pI: 6.5) compared to the wild type CRYAB (pI: 6.76).

Bottom Line: Subsequent interrogation of our entire cohort of familial cases identified a second familial case localized to chromosome 11q23 harboring a c.31C>T (p.R11C) mutation.Real-time PCR analysis identified the expression of Cryab in mouse lens as early as embryonic day 15 (E15) that increased significantly until postnatal day 6 (P6) with steady level of expression thereafter.Here, we report two novel missense mutations, p.R11C and p.R12C, in CRYAB associated with autosomal recessive congenital nuclear cataracts.

View Article: PubMed Central - PubMed

Affiliation: Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, United States of America.

ABSTRACT

Purpose: This study was initiated to identify causal mutations responsible for autosomal recessive congenital cataracts in consanguineous familial cases.

Methods: Affected individuals underwent a detailed ophthalmological and clinical examination, and slit-lamp photographs were ascertained for affected individuals who have not yet been operated for the removal of the cataractous lens. Blood samples were obtained, and genomic DNA was extracted from white blood cells. A genome-wide scan was completed with short tandem repeat (STR) markers, and the logarithm of odds (LOD) scores were calculated. Protein coding exons of CRYAB were sequenced, bi-directionally. Evolutionary conservation was investigated by aligning CRYAB orthologues, and the expression of Cryab in embryonic and postnatal mice lens was investigated with TaqMan probe.

Results: The clinical and ophthalmological examinations suggested that all affected individuals had nuclear cataracts. Genome-wide linkage analysis suggested a potential region on chromosome 11q23 harboring CRYAB. DNA sequencing identified a missense variation: c.34C>T (p.R12C) in CRYAB that segregated with the disease phenotype in the family. Subsequent interrogation of our entire cohort of familial cases identified a second familial case localized to chromosome 11q23 harboring a c.31C>T (p.R11C) mutation. In silico analyses suggested that the mutations identified in familial cases, p.R11C and p.R12C will not be tolerated by the three-dimensional structure of CRYAB. Real-time PCR analysis identified the expression of Cryab in mouse lens as early as embryonic day 15 (E15) that increased significantly until postnatal day 6 (P6) with steady level of expression thereafter.

Conclusion: Here, we report two novel missense mutations, p.R11C and p.R12C, in CRYAB associated with autosomal recessive congenital nuclear cataracts.

No MeSH data available.


Related in: MedlinePlus