chr15-40602900-G-A

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBS1_Supporting

The NM_144508.5(KNL1):​c.-17-15G>A variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000771 in 1,413,026 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.00019 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000063 ( 1 hom. )

Consequence

KNL1
NM_144508.5 intron

Scores

2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -0.00600

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: Likely_benign. The variant received -5 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.86).
BS1
Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.000191 (29/152148) while in subpopulation EAS AF = 0.0027 (14/5190). AF 95% confidence interval is 0.00163. There are 0 homozygotes in GnomAd4. There are 15 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KNL1NM_144508.5 linkc.-17-15G>A intron_variant Intron 1 of 25 ENST00000399668.7 NP_653091.3 Q8NG31-2
KNL1NM_170589.5 linkc.-17-15G>A intron_variant Intron 1 of 26 NP_733468.3 Q8NG31-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KNL1ENST00000399668.7 linkc.-17-15G>A intron_variant Intron 1 of 25 1 NM_144508.5 ENSP00000382576.3 Q8NG31-2

Frequencies

GnomAD3 genomes
AF:
0.000184
AC:
28
AN:
152032
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000290
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00269
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.000479
GnomAD2 exomes
AF:
0.000193
AC:
46
AN:
238834
AF XY:
0.000170
show subpopulations
Gnomad AFR exome
AF:
0.000133
Gnomad AMR exome
AF:
0.0000312
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00226
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000689
GnomAD4 exome
AF:
0.0000634
AC:
80
AN:
1260878
Hom.:
1
Cov.:
18
AF XY:
0.0000455
AC XY:
29
AN XY:
636790
show subpopulations
African (AFR)
AF:
0.0000346
AC:
1
AN:
28876
American (AMR)
AF:
0.0000481
AC:
2
AN:
41546
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
24602
East Asian (EAS)
AF:
0.000726
AC:
28
AN:
38554
South Asian (SAS)
AF:
0.00
AC:
0
AN:
79602
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52224
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5346
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
936584
Other (OTH)
AF:
0.000915
AC:
49
AN:
53544
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.472
Heterozygous variant carriers
0
3
6
10
13
16
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
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
GnomAD4 genome
AF:
0.000191
AC:
29
AN:
152148
Hom.:
0
Cov.:
32
AF XY:
0.000202
AC XY:
15
AN XY:
74378
show subpopulations
African (AFR)
AF:
0.000289
AC:
12
AN:
41492
American (AMR)
AF:
0.0000655
AC:
1
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00270
AC:
14
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10564
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68016
Other (OTH)
AF:
0.000948
AC:
2
AN:
2110
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.507
Heterozygous variant carriers
0
2
3
5
6
8
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:
0.000260
Hom.:
0
Bravo
AF:
0.000249
Asia WGS
AF:
0.00260
AC:
9
AN:
3476

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

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
BayesDel_noAF
Benign
-0.86
CADD
Benign
1.1
DANN
Benign
0.50
PhyloP100
-0.0060

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: rs186815033; hg19: chr15-40895098; API