15-40625535-C-T

Variant summary

Our verdict is Benign. The variant received -14 ACMG points: 0P and 14B. BP4_StrongBP6BP7BS1BS2

The NM_144508.5(KNL1):​c.5271C>T​(p.Cys1757Cys) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000426 in 1,607,592 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0022 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00024 ( 2 hom. )

Consequence

KNL1
NM_144508.5 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:4

Conservation

PhyloP100: -0.167

Publications

0 publications found
Variant links:
Genes affected
KNL1 (HGNC:24054): (kinetochore scaffold 1) The protein encoded by this gene is a component of the multiprotein assembly that is required for creation of kinetochore-microtubule attachments and chromosome segregation. The encoded protein functions as a scaffold for proteins that influence the spindle assembly checkpoint during the eukaryotic cell cycle and it interacts with at least five different kinetochore proteins and two checkpoint kinases. In adults, this gene is predominantly expressed in normal testes, various cancer cell lines and primary tumors from other tissues and is ubiquitously expressed in fetal tissues. This gene was originally identified as a fusion partner with the mixed-lineage leukemia (MLL) gene in t(11;15)(q23;q14). Mutations in this gene cause autosomal recessive primary microcephaly-4 (MCPH4). Alternative splicing results in multiple transcript variants encoding different isoforms. Additional splice variants have been described but their biological validity has not been confirmed. [provided by RefSeq, Jan 2013]
KNL1 Gene-Disease associations (from GenCC):
  • microcephaly 4, primary, autosomal recessive
    Inheritance: AR Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • autosomal recessive primary microcephaly
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -14 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.84).
BP6
Variant 15-40625535-C-T is Benign according to our data. Variant chr15-40625535-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 210571.
BP7
Synonymous conserved (PhyloP=-0.167 with no splicing effect.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00223 (339/151940) while in subpopulation AFR AF = 0.0077 (319/41428). AF 95% confidence interval is 0.007. There are 0 homozygotes in GnomAd4. There are 178 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High Homozygotes in GnomAdExome4 at 2 AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KNL1NM_144508.5 linkc.5271C>T p.Cys1757Cys synonymous_variant Exon 10 of 26 ENST00000399668.7 NP_653091.3 Q8NG31-2
KNL1NM_170589.5 linkc.5349C>T p.Cys1783Cys synonymous_variant Exon 11 of 27 NP_733468.3 Q8NG31-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KNL1ENST00000399668.7 linkc.5271C>T p.Cys1757Cys synonymous_variant Exon 10 of 26 1 NM_144508.5 ENSP00000382576.3 Q8NG31-2

Frequencies

GnomAD3 genomes
AF:
0.00221
AC:
336
AN:
151822
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00765
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000525
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000736
Gnomad OTH
AF:
0.00336
GnomAD2 exomes
AF:
0.000638
AC:
155
AN:
242774
AF XY:
0.000561
show subpopulations
Gnomad AFR exome
AF:
0.00850
Gnomad AMR exome
AF:
0.000459
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000540
Gnomad OTH exome
AF:
0.000681
GnomAD4 exome
AF:
0.000238
AC:
346
AN:
1455652
Hom.:
2
Cov.:
33
AF XY:
0.000224
AC XY:
162
AN XY:
724198
show subpopulations
African (AFR)
AF:
0.00693
AC:
227
AN:
32778
American (AMR)
AF:
0.000585
AC:
25
AN:
42770
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25894
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39650
South Asian (SAS)
AF:
0.0000353
AC:
3
AN:
84990
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53308
Middle Eastern (MID)
AF:
0.00175
AC:
10
AN:
5726
European-Non Finnish (NFE)
AF:
0.0000423
AC:
47
AN:
1110464
Other (OTH)
AF:
0.000566
AC:
34
AN:
60072
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
Heterozygous variant carriers
0
20
39
59
78
98
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
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:
0.00223
AC:
339
AN:
151940
Hom.:
0
Cov.:
32
AF XY:
0.00240
AC XY:
178
AN XY:
74272
show subpopulations
African (AFR)
AF:
0.00770
AC:
319
AN:
41428
American (AMR)
AF:
0.000524
AC:
8
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5172
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4816
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10514
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000736
AC:
5
AN:
67960
Other (OTH)
AF:
0.00332
AC:
7
AN:
2108
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.505
Heterozygous variant carriers
0
18
36
55
73
91
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
4
8
12
16
20
<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:
0.00183
Hom.:
1
Bravo
AF:
0.00237
EpiCase
AF:
0.000327
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:4
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not specified Uncertain:1Benign:1
Jan 28, 2015
Genetic Services Laboratory, University of Chicago
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 24, 2017
Eurofins Ntd Llc (ga)
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:2
Dec 31, 2019
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 12, 2021
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Microcephaly 4, primary, autosomal recessive Benign:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.84
CADD
Benign
0.20
DANN
Benign
0.18
PhyloP100
-0.17
Mutation Taster
=100/0
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
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: rs191249840; hg19: chr15-40917733; API