4-55435558-G-A

Variant names:

• chr4-55435558-G-A
• rs1722810655
• NM_004898.4:c.2398C>T

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 2P and 6B. PM2 BP4_Moderate BS2

The NM_004898.4(CLOCK):​c.2398C>T​(p.Leu800Phe) variant causes a missense change. The variant allele was found at a frequency of 0.00000342 in 1,461,682 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: CLOCK NM_004898.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.69
• Publications: 0 publications found

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]

TMEM165 Gene-Disease associations (from GenCC):

• TMEM165-congenital disorder of glycosylation

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), G2P, Orphanet, Ambry Genetics

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.11318135).
• BS2: High AC in GnomAdExome4 at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CLOCK	NM_004898.4	c.2398C>T	p.Leu800Phe	missense_variant	Exon 23 of 23	ENST00000513440.6	NP_004889.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CLOCK	ENST00000513440.6	c.2398C>T	p.Leu800Phe	missense_variant	Exon 23 of 23	1	NM_004898.4	ENSP00000426983.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461682 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727156

African (AFR) AF: 0.0000598 AC: 2 AN: 33464

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111858

Other (OTH) AF: 0.0000331 AC: 2 AN: 60382

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Apr 25, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2398C>T (p.L800F) alteration is located in exon 23 (coding exon 20) of the CLOCK gene. This alteration results from a C to T substitution at nucleotide position 2398, causing the leucine (L) at amino acid position 800 to be replaced by a phenylalanine (F). 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	0.29
BayesDel_addAF	Benign	-0.18	T
BayesDel_noAF	Benign	-0.49
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.12	T;T;T
Eigen	Benign	-0.046
Eigen_PC	Benign	0.057
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Uncertain	0.87	D;.;.
M_CAP	Benign	0.040	D
MetaRNN	Benign	0.11	T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.9	L;L;L
PhyloP100		4.7
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	-1.5	N;N;N
REVEL	Benign	0.11
Sift	Uncertain	0.016	D;D;D
Sift4G	Uncertain	0.0090	D;D;D
Polyphen		0.011	B;B;B
Vest4		0.26
MutPred		0.29		Gain of glycosylation at S797 (P = 0.1068);Gain of glycosylation at S797 (P = 0.1068);Gain of glycosylation at S797 (P = 0.1068);
MVP		0.20
MPC		1.1
ClinPred		0.90	D
GERP RS		3.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.15
gMVP		0.50
Mutation Taster		=67/33	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.12		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1722810655; hg19: chr4-56301725;