6-26107913-T-C

Position:

• chr6-26107913-T-C

Variant summary

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

The NM_005323.4(H1-6):​c.181A>G​(p.Met61Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 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. M61T) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: H1-6 NM_005323.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.466

Genes affected

H1-6 (HGNC:4720): (H1.6 linker histone, cluster member) Histones are basic nuclear proteins responsible for nucleosome structure of the chromosomal fiber in eukaryotes. Two molecules of each of the four core histones (H2A, H2B, H3, and H4) form an octamer, around which approximately 146 bp of DNA is wrapped in repeating units, called nucleosomes. The linker histone, H1, interacts with linker DNA between nucleosomes and functions in the compaction of chromatin into higher order structures. This gene is intronless and encodes a replication-dependent histone that is a member of the histone H1 family. Transcripts from this gene lack polyA tails but instead contain a palindromic termination element. This gene is found in the large histone gene cluster on chromosome 6. [provided by RefSeq, Aug 2015]

H2BC4 (HGNC:4757): (H2B clustered histone 4) Histones are basic nuclear proteins that are responsible for the nucleosome structure of the chromosomal fiber in eukaryotes. Two molecules of each of the four core histones (H2A, H2B, H3, and H4) form an octamer, around which approximately 146 bp of DNA is wrapped in repeating units, called nucleosomes. The linker histone, H1, interacts with linker DNA between nucleosomes and functions in the compaction of chromatin into higher order structures. The protein has antibacterial and antifungal antimicrobial activity. The main transcript variant of this gene is intronless and encodes a replication-dependent histone that is a member of the histone H2B family. This transcript variant lacks a polyA tail but instead contains a palindromic termination element. This gene is found in the large histone gene cluster on chromosome 6. [provided by RefSeq, Apr 2020]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
H1-6	NM_005323.4	c.181A>G	p.Met61Val	missense_variant	1/1	ENST00000338379.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
H1-6	ENST00000338379.6	c.181A>G	p.Met61Val	missense_variant	1/1		NM_005323.4	P1
H2BC4	ENST00000707188.1	c.*9+15602A>G		intron_variant, NMD_transcript_variant

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000795 AC: 2 AN: 251416 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135876

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461888 Hom.: 0 Cov.: 37 AF XY: 0.00000275 AC XY: 2 AN XY: 727248

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000447

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

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

Feb 28, 2023

The c.181A>G (p.M61V) alteration is located in exon 1 (coding exon 1) of the HIST1H1T gene. This alteration results from a A to G substitution at nucleotide position 181, causing the methionine (M) at amino acid position 61 to be replaced by a valine (V). 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	0.15
BayesDel_addAF	Benign	-0.36	T
BayesDel_noAF	Benign	-0.58
CADD	Benign	0.62
DANN	Benign	0.44
DEOGEN2	Benign	0.044	T
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.0
FATHMM_MKL	Benign	0.18	N
LIST_S2	Benign	0.82	T
M_CAP	Benign	0.0059	T
MetaRNN	Benign	0.081	T
MetaSVM	Benign	-0.92	T
MutationAssessor	Benign	-1.1	N
MutationTaster	Benign	0.90	D
PrimateAI	Benign	0.27	T
PROVEAN	Benign	0.070	N
REVEL	Benign	0.046
Sift	Benign	0.86	T
Sift4G	Benign	1.0	T
Polyphen		0.0070	B
Vest4		0.22
MutPred		0.49		Gain of catalytic residue at M61 (P = 0.0635);
MVP		0.014
ClinPred		0.033	T
GERP RS		1.7
Varity_R		0.077
gMVP		0.14

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.22		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.22		Position offset: 7

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

Publications

LitVar

Other links and lift over

dbSNP: rs1235384395; hg19: chr6-26108141;