7-66638273-G-C

Variant names:

• chr7-66638273-G-C
• rs774026720
• NM_153033.5:c.335G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1 PM2 PM5 PP3

The NM_153033.5(KCTD7):​c.335G>C​(p.Arg112Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,184 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 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. R112C) has been classified as Likely pathogenic.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: KCTD7 NM_153033.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.24
• Publications: 6 publications found

Genes affected

KCTD7 (HGNC:21957): (potassium channel tetramerization domain containing 7) This gene encodes a member of the potassium channel tetramerization domain-containing protein family. Family members are identified on a structural basis and contain an amino-terminal domain similar to the T1 domain present in the voltage-gated potassium channel. Mutations in this gene have been associated with progressive myoclonic epilepsy-3. Alternative splicing results in multiple transcript variants.[provided by RefSeq, Jan 2011]

KCTD7 Gene-Disease associations (from GenCC):

• progressive myoclonic epilepsy type 3

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), Orphanet
• progressive myoclonus epilepsy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen

ENSG00000284461 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_153033.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr7-66638272-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1000932.
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_153033.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCTD7	NM_153033.5	MANE Select	c.335G>C	p.Arg112Pro	missense	Exon 3 of 4	NP_694578.1
	KCTD7	NM_001167961.2		c.335G>C	p.Arg112Pro	missense	Exon 3 of 5	NP_001161433.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCTD7	ENST00000639828.2	TSL:2 MANE Select	c.335G>C	p.Arg112Pro	missense	Exon 3 of 4	ENSP00000492240.1
	KCTD7	ENST00000443322.1	TSL:1	c.335G>C	p.Arg112Pro	missense	Exon 3 of 5	ENSP00000411624.1
	ENSG00000284461	ENST00000503687.2	TSL:2	n.165G>C		non_coding_transcript_exon	Exon 2 of 13	ENSP00000421074.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152184 Hom.: 0 Cov.: 32

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

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152184 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74326

African (AFR) AF: 0.00 AC: 0 AN: 41440

American (AMR) AF: 0.00 AC: 0 AN: 15282

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5194

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68034

Other (OTH) AF: 0.000478 AC: 1 AN: 2092

Alfa AF: 0.00 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.27
CADD	Pathogenic	35
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.87	D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	D
M_CAP	Pathogenic	0.35	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Uncertain	0.47	D
MutationAssessor	Pathogenic	4.4	H
PhyloP100		9.2
PrimateAI	Uncertain	0.73	T
PROVEAN	Pathogenic	-6.8	D
REVEL	Pathogenic	0.83
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.88		Loss of stability (P = 0.0601)
MVP		0.94
ClinPred		1.0	D
GERP RS		5.6
Varity_R		0.98
gMVP		0.98
Mutation Taster		=9/91	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.54		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.54		Position offset: 6

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs774026720; hg19: chr7-66103260;