17-46171417-G-A

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PVS1PP5

The NM_015443.4(KANSL1):c.727C>T(p.Gln243*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000109 in 1,461,780 control chromosomes in the GnomAD database, with no homozygous occurrence. There is a variant allele frequency bias in the population database for this variant (GnomAdExome4), which may indicate mosaicism or somatic mutations in the reference population data. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. Q243Q) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0 ( 0 hom., cov: 35)

Exomes 𝑓: 0.000011 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

KANSL1
NM_015443.4 stop_gained

Scores

Clinical Significance

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

Conservation

PhyloP100: 2.40

Publications

6 publications found

Variant links:

Genes affected

KANSL1 (HGNC:24565): (KAT8 regulatory NSL complex subunit 1) This gene encodes a nuclear protein that is a subunit of two protein complexes involved with histone acetylation, the MLL1 complex and the NSL1 complex. The encoded protein has been implicated in a variety of cellular processes including enhancer regulation, cell proliferation, and mitosis. Mutations in this gene are associated with Koolen-de Vries Syndrome. [provided by RefSeq, May 2022]

KANSL1 Gene-Disease associations (from GenCC):

Koolen-de Vries syndrome
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), ClinGen
Koolen-de Vries syndrome due to a point mutation
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

KANSL1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PP5

Variant 17-46171417-G-A is Pathogenic according to our data. Variant chr17-46171417-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1062873.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_015443.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
KANSL1	NM_015443.4	MANE Select	c.727C>T	p.Gln243*	stop_gained	Exon 2 of 15	NP_056258.1
KANSL1	NM_001193466.2		c.727C>T	p.Gln243*	stop_gained	Exon 2 of 15	NP_001180395.1
KANSL1	NM_001379198.1		c.727C>T	p.Gln243*	stop_gained	Exon 3 of 16	NP_001366127.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
KANSL1	ENST00000432791.7	TSL:1 MANE Select	c.727C>T	p.Gln243*	stop_gained	Exon 2 of 15	ENSP00000387393.3
KANSL1	ENST00000262419.10	TSL:1	c.727C>T	p.Gln243*	stop_gained	Exon 2 of 15	ENSP00000262419.6
KANSL1	ENST00000572904.6	TSL:5	c.727C>T	p.Gln243*	stop_gained	Exon 2 of 15	ENSP00000461484.1

Frequencies

GnomAD3 genomes

AF:

0.00

AC:

AN:

152164

Hom.:

Cov.:

Gnomad AFR

AF:

0.00

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:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251178

AF XY:

0.00000737

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000109

AC:

AN:

1461780

Hom.:

Cov.:

AF XY:

0.0000124

AC XY:

AN XY:

727196

show subpopulations

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44712

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26130

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86246

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53404

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000144

AC:

AN:

1111950

Other (OTH)

AF:

0.00

AC:

AN:

60392

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.288

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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

Data not reliable, filtered out with message: AC0

AF:

0.00

AC:

AN:

152164

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74324

African (AFR)

AF:

0.00

AC:

AN:

41424

American (AMR)

AF:

0.00

AC:

AN:

15282

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5190

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10600

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68046

Other (OTH)

AF:

0.00

AC:

AN:

2092

Alfa

AF:

0.00000336

Hom.:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:1Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Koolen-de Vries syndrome

Uncertain:1Benign:1

Apr 10, 2024

Laboratory of Functional Genomics, Research Centre for Medical Genetics

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

The proband, a girl diagnosed with developmental and epileptic encephalopathies (DEEs), underwent whole-genome sequencing (WGS). Two variants were identified: a frameshift variant in the HNRNPU gene and a nonsense variant in the KANSL1 gene. Segregation analysis revealed that the HNRNPU variant is de novo, leading to its classification as pathogenic and causative of the proband's condition. Conversely, the KANSL1 variant was inherited from her healthy mother. Further investigation through WGS uncovered a common duplication involving exons 1 and 2 of the KANSL1 gene. RNA analysis confirmed the presence of this duplication and localized the KANSL1 variant within the duplicated region. Since the duplicated locus of KANSL1 is non-functional, it does not contribute to the pathological phenotype. Therefore, based on these findings, the KANSL1 variant is classified as benign.

Sep 01, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

not provided

Pathogenic:1

Jan 01, 2024

CeGaT Center for Human Genetics Tuebingen

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

KANSL1: PVS1, PM2

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Pathogenic

0.52

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

Eigen

Pathogenic

0.96

Eigen_PC

Pathogenic

0.85

FATHMM_MKL

Uncertain

0.91

PhyloP100

2.4

Vest4

0.32

GERP RS

6.0

PromoterAI

-0.021

Neutral

(source)

Mutation Taster

=2/198

disease causing (fs/PTC)

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over