rs74315399

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong

The NM_170784.3(MKKS):c.169A>G(p.Thr57Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000867 in 1,613,934 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

MKKS
NM_170784.3 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 5.62

Publications

8 publications found

Variant links:

Genes affected

MKKS (HGNC:7108): (MKKS centrosomal shuttling protein) This gene encodes a protein which shares sequence similarity with other members of the type II chaperonin family. The encoded protein is a centrosome-shuttling protein and plays an important role in cytokinesis. This protein also interacts with other type II chaperonin members to form a complex known as the BBSome, which involves ciliary membrane biogenesis. This protein is encoded by a downstream open reading frame (dORF). Several upstream open reading frames (uORFs) have been identified, which repress the translation of the dORF, and two of which can encode small mitochondrial membrane proteins. Mutations in this gene have been observed in patients with Bardet-Biedl syndrome type 6, also known as McKusick-Kaufman syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2023]

MKKS Gene-Disease associations (from GenCC):

McKusick-Kaufman syndrome
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Orphanet
Bardet-Biedl syndrome 6
Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
Bardet-Biedl syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

MKKS links:

ENSG00000285508 (HGNC:):

ENSG00000285508 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 14 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.985

PP5

Variant 20-10413346-T-C is Pathogenic according to our data. Variant chr20-10413346-T-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 5316.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MKKS	NM_170784.3 link	c.169A>G	p.Thr57Ala	missense_variant	Exon 3 of 6	ENST00000347364.7	NP_740754.1	Q9NPJ1B7Z3W9
MKKS	NM_018848.3 link	c.169A>G	p.Thr57Ala	missense_variant	Exon 3 of 6		NP_061336.1	Q9NPJ1B7Z3W9
MKKS	NR_072977.2 link	n.347-4543A>G		intron_variant	Intron 2 of 4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MKKS	ENST00000347364.7 link	c.169A>G	p.Thr57Ala	missense_variant	Exon 3 of 6	1	NM_170784.3	ENSP00000246062.4		Q9NPJ1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152094

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

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:

0.0000199

AC:

AN:

251250

AF XY:

0.0000221

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000821

AC:

AN:

1461840

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

727210

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33478

American (AMR)

AF:

0.0000894

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53414

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000540

AC:

AN:

1111970

Other (OTH)

AF:

0.0000166

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.500

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

AF:

0.0000131

AC:

AN:

152094

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74306

show subpopulations

African (AFR)

AF:

0.0000483

AC:

AN:

41390

American (AMR)

AF:

0.00

AC:

AN:

15270

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5198

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

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:

68016

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00000917

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

McKusick-Kaufman syndrome

Pathogenic:2

May 28, 2019

Mendelics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jul 25, 2023

3billion

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.002%). Predicted Consequence/Location: Protein truncation variants are a common disease-causing mechanism. Functional studies provide strong evidence of the variant having a damaging effect on the gene or gene product (PMID: 18094050). In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.83; 3Cnet: 0.43). Same nucleotide change resulting in same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000005316 /PMID: 10973251). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -

not provided

Pathogenic:2

Apr 28, 2022

Revvity Omics, Revvity

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Sep 25, 2024

GeneDx

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Identified in the heterozygous state in an individual with Bardet-Biedl syndrome, however, a second MKKS variant was not identified (PMID: 10973251); Published functional studies demonstrate a damaging effect; protein degradation and solubility is altered in transiently transfected HEX293 cells when compared with WT cells (PMID: 18094050); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 12107442, 20498079, 22446187, 26900326, 11179009, 20080638, 18094050, 10973251, 38694397, 31964843) -

Bardet-Biedl syndrome 6

Pathogenic:2

Feb 05, 2024

Baylor Genetics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Sep 01, 2000

OMIM

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

- -

Bardet-Biedl syndrome;C0948368:McKusick-Kaufman syndrome

Pathogenic:1

Oct 13, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 57 of the MKKS protein (p.Thr57Ala). This variant is present in population databases (rs74315399, gnomAD 0.01%). This missense change has been observed in individual(s) with clinical features of Bardet-Biedl syndrome (PMID: 10973251; Invitae; external communication). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 5316). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on MKKS protein function. Experimental studies have shown that this missense change affects MKKS function (PMID: 18094050, 20080638, 20498079, 22446187, 22500027, 26900326). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.25

BayesDel_addAF

Pathogenic

0.26

BayesDel_noAF

Pathogenic

0.37

CADD

Uncertain

(source)

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.91

D;D

Eigen

Uncertain

0.36

Eigen_PC

Uncertain

0.29

FATHMM_MKL

Uncertain

0.87

LIST_S2

Benign

0.80

.;T

M_CAP

Uncertain

0.096

MetaRNN

Pathogenic

0.98

D;D

MetaSVM

Uncertain

0.70

MutationAssessor

Pathogenic

3.0

M;M

PhyloP100

5.6

PrimateAI

Benign

0.44

PROVEAN

Uncertain

-3.6

D;D

REVEL

Pathogenic

0.83

Sift

Pathogenic

0.0

D;D

Sift4G

Pathogenic

0.0

D;D

Polyphen

1.0

D;D

Vest4

0.98

MutPred

0.91

Gain of sheet (P = 0.0477);Gain of sheet (P = 0.0477);

MVP

0.94

MPC

0.51

ClinPred

0.54

GERP RS

5.0

Varity_R

0.62

gMVP

0.81

Mutation Taster

=26/74

disease causing (ClinVar)

(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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over