chr20-10405647-C-G

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_170784.3(MKKS):c.1313G>C(p.Cys438Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,196 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C438Y) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Consequence

MKKS
NM_170784.3 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 0.533

Publications

1 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:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MKKS	NM_170784.3 link	c.1313G>C	p.Cys438Ser	missense_variant	Exon 6 of 6	ENST00000347364.7	NP_740754.1	Q9NPJ1B7Z3W9
MKKS	NM_018848.3 link	c.1313G>C	p.Cys438Ser	missense_variant	Exon 6 of 6		NP_061336.1	Q9NPJ1B7Z3W9
MKKS	NR_072977.2 link	n.674G>C		non_coding_transcript_exon_variant	Exon 5 of 5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
MKKS	ENST00000347364.7 link	c.1313G>C	p.Cys438Ser	missense_variant	Exon 6 of 6	1	NM_170784.3	ENSP00000246062.4	Q9NPJ1
MKKS	ENST00000399054.6 link	c.1313G>C	p.Cys438Ser	missense_variant	Exon 6 of 6	1		ENSP00000382008.2	Q9NPJ1
MKKS	ENST00000651692.1 link	c.1313G>C	p.Cys438Ser	missense_variant	Exon 7 of 7			ENSP00000498849.1	Q9NPJ1
MKKS	ENST00000652676.1 link	n.957G>C		non_coding_transcript_exon_variant	Exon 7 of 7

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152196

Hom.:

Cov.:

show subpopulations

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:

0.000478

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251164

AF XY:

0.00000736

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:

0.00000881

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

Cov.:

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152196

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74366

show subpopulations

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

African (AFR)

AF:

0.00

AC:

AN:

41448

American (AMR)

AF:

0.00

AC:

AN:

15278

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5200

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68026

Other (OTH)

AF:

0.000478

AC:

AN:

2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 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: 0.375

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome 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

ExAC

AF:

0.00000824

AC:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.12

BayesDel_addAF

Uncertain

0.10

BayesDel_noAF

Benign

-0.090

CADD

Benign

(source)

DANN

Uncertain

0.98

DEOGEN2

Pathogenic

0.80

D;D

Eigen

Benign

-0.38

Eigen_PC

Benign

-0.54

FATHMM_MKL

Benign

0.69

LIST_S2

Benign

0.63

.;T

M_CAP

Benign

0.082

MetaRNN

Uncertain

0.59

D;D

MetaSVM

Uncertain

0.16

MutationAssessor

Pathogenic

3.0

M;M

PhyloP100

0.53

PrimateAI

Benign

0.33

PROVEAN

Pathogenic

-4.6

D;D

REVEL

Uncertain

0.52

Sift

Uncertain

0.0030

D;D

Sift4G

Uncertain

0.0090

D;D

Polyphen

1.0

D;D

Vest4

0.38

MutPred

0.58

Gain of disorder (P = 0.0035);Gain of disorder (P = 0.0035);

MVP

0.96

MPC

0.37

ClinPred

0.97

GERP RS

0.34

Varity_R

0.44

gMVP

0.77

Mutation Taster

=83/17

polymorphism

(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

Computational scores

Splicing

Publications

Other links and lift over