chr22-25229578-C-T

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 3P and 8B. PM1PP2BS1BS2

The NM_000496.3(CRYBB2):​c.449C>T​(p.Thr150Met) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.000204 in 1,614,060 control chromosomes in the GnomAD database, including 1 homozygotes. 2/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T150R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00025 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00020 ( 1 hom. )

Consequence

CRYBB2
NM_000496.3 missense, splice_region

Scores

7
9
3
Splicing: ADA: 0.9394
1
1

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 4.39

Publications

17 publications found
Variant links:
Genes affected
CRYBB2 (HGNC:2398): (crystallin beta B2) Crystallins are separated into two classes: taxon-specific, or enzyme, and ubiquitous. The latter class constitutes the major proteins of vertebrate eye lens and maintains the transparency and refractive index of the lens. Since lens central fiber cells lose their nuclei during development, these crystallins are made and then retained throughout life, making them extremely stable proteins. Mammalian lens crystallins are divided into alpha, beta, and gamma families; beta and gamma crystallins are also considered as a superfamily. Alpha and beta families are further divided into acidic and basic groups. Seven protein regions exist in crystallins: four homologous motifs, a connecting peptide, and N- and C-terminal extensions. Beta-crystallins, the most heterogeneous, differ by the presence of the C-terminal extension (present in the basic group, none in the acidic group). Beta-crystallins form aggregates of different sizes and are able to self-associate to form dimers or to form heterodimers with other beta-crystallins. This gene, a beta basic group member, is part of a gene cluster with beta-A4, beta-B1, and beta-B3. A chain-terminating mutation was found to cause type 2 cerulean cataracts. [provided by RefSeq, Jul 2008]
CRYBB2 Gene-Disease associations (from GenCC):
  • cataract 3 multiple types
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P, Laboratory for Molecular Medicine
  • cataract - microcornea syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • cerulean cataract
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • early-onset nuclear cataract
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • early-onset posterior subcapsular cataract
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • early-onset sutural cataract
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • pulverulent cataract
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • total early-onset cataract
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_000496.3
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 13 curated pathogenic missense variants (we use a threshold of 10). The gene has 2 curated benign missense variants. Gene score misZ: 1.0723 (below the threshold of 3.09). Trascript score misZ: 1.7369 (below the threshold of 3.09). GenCC associations: The gene is linked to cataract 3 multiple types, pulverulent cataract, cataract - microcornea syndrome, early-onset posterior subcapsular cataract, total early-onset cataract, early-onset nuclear cataract, cerulean cataract, early-onset sutural cataract.
BS1
Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.000249 (38/152404) while in subpopulation NFE AF = 0.000441 (30/68046). AF 95% confidence interval is 0.000317. There are 0 homozygotes in GnomAd4. There are 12 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High AC in GnomAd4 at 38 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CRYBB2NM_000496.3 linkc.449C>T p.Thr150Met missense_variant, splice_region_variant Exon 5 of 6 ENST00000398215.3 NP_000487.1 P43320R4UMM2
CRYBB2XM_006724141.4 linkc.449C>T p.Thr150Met missense_variant, splice_region_variant Exon 5 of 6 XP_006724204.1 P43320R4UMM2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CRYBB2ENST00000398215.3 linkc.449C>T p.Thr150Met missense_variant, splice_region_variant Exon 5 of 6 1 NM_000496.3 ENSP00000381273.2 P43320
CRYBB2ENST00000651629.1 linkc.449C>T p.Thr150Met missense_variant, splice_region_variant Exon 5 of 6 ENSP00000498905.1 P43320

Frequencies

GnomAD3 genomes
AF:
0.000250
AC:
38
AN:
152286
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000964
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000385
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000111
AC:
28
AN:
251276
AF XY:
0.0000736
show subpopulations
Gnomad AFR exome
AF:
0.000123
Gnomad AMR exome
AF:
0.0000579
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000217
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.000150
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.000200
AC:
292
AN:
1461656
Hom.:
1
Cov.:
32
AF XY:
0.000187
AC XY:
136
AN XY:
727134
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.0000447
AC:
2
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000504
AC:
2
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.0000936
AC:
5
AN:
53414
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
0.000246
AC:
273
AN:
1111796
Other (OTH)
AF:
0.000132
AC:
8
AN:
60388
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.322
Heterozygous variant carriers
0
18
37
55
74
92
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.000249
AC:
38
AN:
152404
Hom.:
0
Cov.:
32
AF XY:
0.000161
AC XY:
12
AN XY:
74532
show subpopulations
African (AFR)
AF:
0.0000962
AC:
4
AN:
41600
American (AMR)
AF:
0.0000653
AC:
1
AN:
15312
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000386
AC:
2
AN:
5186
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10632
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000441
AC:
30
AN:
68046
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.416
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.000230
Hom.:
0
Bravo
AF:
0.000181
ExAC
AF:
0.000148
AC:
18
EpiCase
AF:
0.000164
EpiControl
AF:
0.0000593

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.29
BayesDel_addAF
Benign
-0.026
T
BayesDel_noAF
Uncertain
-0.010
CADD
Pathogenic
33
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.55
D
Eigen
Pathogenic
0.77
Eigen_PC
Pathogenic
0.70
FATHMM_MKL
Uncertain
0.92
D
LIST_S2
Uncertain
0.97
D
M_CAP
Uncertain
0.14
D
MetaRNN
Uncertain
0.50
T
MetaSVM
Uncertain
0.37
D
MutationAssessor
Pathogenic
3.0
M
PhyloP100
4.4
PrimateAI
Pathogenic
0.82
D
PROVEAN
Pathogenic
-4.8
D
REVEL
Pathogenic
0.67
Sift
Uncertain
0.0090
D
Sift4G
Uncertain
0.0030
D
Polyphen
1.0
D
Vest4
0.39
MVP
0.71
MPC
1.4
ClinPred
0.79
D
GERP RS
5.0
Varity_R
0.58
Mutation Taster
=22/78
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.94
dbscSNV1_RF
Pathogenic
0.76
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs4049504; hg19: chr22-25625545; COSMIC: COSV68005343; API