4-55443769-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_004898.4(CLOCK):c.1820T>G(p.Ile607Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,810 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I607F) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CLOCK NM_004898.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.48

Genes affected

CLOCK (HGNC:2082): (clock circadian regulator) The protein encoded by this gene plays a central role in the regulation of circadian rhythms. The protein encodes a transcription factor of the basic helix-loop-helix (bHLH) family and contains DNA binding histone acetyltransferase activity. The encoded protein forms a heterodimer with ARNTL (BMAL1) that binds E-box enhancer elements upstream of Period (PER1, PER2, PER3) and Cryptochrome (CRY1, CRY2) genes and activates transcription of these genes. PER and CRY proteins heterodimerize and repress their own transcription by interacting in a feedback loop with CLOCK/ARNTL complexes. Polymorphisms in this gene may be associated with behavioral changes in certain populations and with obesity and metabolic syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2014]

TMEM165 (HGNC:30760): (transmembrane protein 165) This gene encodes a predicted transmembrane protein with a perinuclear Golgi-like distribution in fibroblasts. Mutations in this gene are associated with the autosomal recessive disorder congenital disorder of glycosylation, type IIk. Knockdown of this gene's expression causes decreased sialylation in HEK cells and suggests this gene plays a role in terminal Golgi glycosylation. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2012]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1221267).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CLOCK	NM_004898.4	c.1820T>G	p.Ile607Ser	missense_variant	20/23	ENST00000513440.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CLOCK	ENST00000513440.6	c.1820T>G	p.Ile607Ser	missense_variant	20/23	1	NM_004898.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461810 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727202

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.0000189

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 27, 2023

The c.1820T>G (p.I607S) alteration is located in exon 20 (coding exon 17) of the CLOCK gene. This alteration results from a T to G substitution at nucleotide position 1820, causing the isoleucine (I) at amino acid position 607 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.47
Cadd	Benign	23
Dann	Uncertain	0.98
DEOGEN2	Benign	0.067	T;T;T
Eigen	Benign	-0.26
Eigen_PC	Benign	-0.056
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.87	D;.;.
M_CAP	Benign	0.0062	T
MetaRNN	Benign	0.12	T;T;T
MetaSVM	Benign	-0.98	T
MutationAssessor	Benign	1.5	L;L;L
MutationTaster	Benign	0.96	N;N;N
PrimateAI	Benign	0.43	T
PROVEAN	Benign	-0.97	N;N;N
REVEL	Benign	0.055
Sift	Benign	0.15	T;T;T
Sift4G	Benign	0.45	T;T;T
Polyphen		0.0	B;B;B
Vest4		0.41
MutPred		0.21		Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);Loss of sheet (P = 0.0315);
MVP		0.18
MPC		0.46
ClinPred		0.37	T
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.11
gMVP		0.29

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs898273156; hg19: chr4-56309936;