chr20-10413233-GA-G

Position:

• chr20-10413233-GA-G

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_170784.3(MKKS):​c.281del​(p.Phe94SerfsTer9) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000041 in 1,461,876 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (no stars). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: MKKS NM_170784.3 frameshift
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 8.63

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]

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 20-10413233-GA-G is Pathogenic according to our data. Variant chr20-10413233-GA-G is described in ClinVar as [Pathogenic]. Clinvar id is 5313.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr20-10413233-GA-G is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MKKS	NM_170784.3	c.281del	p.Phe94SerfsTer9	frameshift_variant	3/6	ENST00000347364.7	NP_740754.1
MKKS	NM_018848.3	c.281del	p.Phe94SerfsTer9	frameshift_variant	3/6		NP_061336.1
MKKS	NR_072977.2	n.347-4431del		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MKKS	ENST00000347364.7	c.281del	p.Phe94SerfsTer9	frameshift_variant	3/6	1	NM_170784.3	ENSP00000246062	P1
MKKS	ENST00000399054.6	c.281del	p.Phe94SerfsTer9	frameshift_variant	3/6	1		ENSP00000382008	P1
MKKS	ENST00000651692.1	c.281del	p.Phe94SerfsTer9	frameshift_variant	4/7			ENSP00000498849	P1
MKKS	ENST00000652676.1	n.459-534del		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000410 AC: 6 AN: 1461876 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727238

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000540

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Bardet-Biedl syndrome 6 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Sep 01, 2000

- -

Computational scores

Source: dbNSFP v4.3

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

LitVar

Other links and lift over

dbSNP: rs587777827; hg19: chr20-10393881;