15-40621478-A-G

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_144508.5(KNL1):​c.1214A>G​(p.Asp405Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00045 in 1,613,858 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00032 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00046 ( 0 hom. )

Consequence

KNL1
NM_144508.5 missense

Scores

1
17

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 1.63

Publications

2 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: Likely_benign. The variant received -4 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.017874599).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KNL1NM_144508.5 linkc.1214A>G p.Asp405Gly missense_variant Exon 10 of 26 ENST00000399668.7 NP_653091.3 Q8NG31-2
KNL1NM_170589.5 linkc.1292A>G p.Asp431Gly missense_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.1214A>G p.Asp405Gly missense_variant Exon 10 of 26 1 NM_144508.5 ENSP00000382576.3 Q8NG31-2

Frequencies

GnomAD3 genomes
AF:
0.000315
AC:
48
AN:
152206
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000482
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00122
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000485
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000270
AC:
67
AN:
248470
AF XY:
0.000237
show subpopulations
Gnomad AFR exome
AF:
0.0000649
Gnomad AMR exome
AF:
0.0000580
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000557
Gnomad NFE exome
AF:
0.000463
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000464
AC:
678
AN:
1461652
Hom.:
0
Cov.:
33
AF XY:
0.000413
AC XY:
300
AN XY:
727126
show subpopulations
African (AFR)
AF:
0.0000597
AC:
2
AN:
33476
American (AMR)
AF:
0.0000447
AC:
2
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39676
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.000975
AC:
52
AN:
53340
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.000528
AC:
587
AN:
1111900
Other (OTH)
AF:
0.000580
AC:
35
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.468
Heterozygous variant carriers
0
36
73
109
146
182
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
24
48
72
96
120
<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:
0.000315
AC:
48
AN:
152206
Hom.:
0
Cov.:
32
AF XY:
0.000296
AC XY:
22
AN XY:
74368
show subpopulations
African (AFR)
AF:
0.0000482
AC:
2
AN:
41460
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3464
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5206
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00122
AC:
13
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000485
AC:
33
AN:
68022
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.489
Heterozygous variant carriers
0
3
6
8
11
14
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:
0.000485
Hom.:
1
Bravo
AF:
0.000253
ESP6500AA
AF:
0.000274
AC:
1
ESP6500EA
AF:
0.000368
AC:
3
ExAC
AF:
0.000273
AC:
33
EpiCase
AF:
0.000545
EpiControl
AF:
0.000474

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:3
Jun 11, 2021
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 27535533) -

Jun 22, 2017
Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 01, 2021
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Uncertain:1
Sep 30, 2022
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1292A>G (p.D431G) alteration is located in exon 11 (coding exon 10) of the KNL1 gene. This alteration results from a A to G substitution at nucleotide position 1292, causing the aspartic acid (D) at amino acid position 431 to be replaced by a glycine (G). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Microcephaly 4, primary, autosomal recessive Uncertain:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.16
BayesDel_addAF
Benign
-0.45
T
BayesDel_noAF
Benign
-0.52
CADD
Benign
9.0
DANN
Benign
0.76
DEOGEN2
Benign
0.20
T;T;.
Eigen
Benign
-0.82
Eigen_PC
Benign
-0.81
FATHMM_MKL
Benign
0.14
N
LIST_S2
Benign
0.65
T;T;T
M_CAP
Benign
0.0045
T
MetaRNN
Benign
0.018
T;T;T
MetaSVM
Benign
-0.98
T
PhyloP100
1.6
PrimateAI
Benign
0.26
T
PROVEAN
Uncertain
-2.7
D;.;D
REVEL
Benign
0.049
Sift
Benign
0.061
T;.;T
Sift4G
Benign
0.60
T;T;T
Polyphen
0.0040
B;.;B
Vest4
0.20
MVP
0.22
MPC
0.046
ClinPred
0.041
T
GERP RS
2.8
Varity_R
0.11
gMVP
0.28
Mutation Taster
=94/6
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: rs113313996; hg19: chr15-40913676; API