chr6-26107486-G-C

Position:

• chr6-26107486-G-C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_005323.4(H1-6):​c.608C>G​(p.Ala203Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000312 in 1,602,162 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., 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: 0.167

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 Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.05702603).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
H1-6	NM_005323.4	c.608C>G	p.Ala203Gly	missense_variant	1/1	ENST00000338379.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
H1-6	ENST00000338379.6	c.608C>G	p.Ala203Gly	missense_variant	1/1		NM_005323.4	P1
H2BC4	ENST00000707188.1	c.*9+16029C>G		intron_variant, NMD_transcript_variant

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152138 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: 0.0000294

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000207 AC: 3 AN: 1450024 Hom.: 0 Cov.: 31 AF XY: 0.00000139 AC XY: 1 AN XY: 721106

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: 0.00000271

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152138 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74308

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

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

Apr 12, 2023

The c.608C>G (p.A203G) alteration is located in exon 1 (coding exon 1) of the HIST1H1T gene. This alteration results from a C to G substitution at nucleotide position 608, causing the alanine (A) at amino acid position 203 to be replaced by a glycine (G). 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	0.089
BayesDel_addAF	Benign	-0.28	T
BayesDel_noAF	Benign	-0.65
CADD	Benign	1.6
DANN	Benign	0.97
DEOGEN2	Benign	0.41	T
Eigen	Benign	-1.0
Eigen_PC	Benign	-1.0
FATHMM_MKL	Benign	0.41	N
LIST_S2	Benign	0.35	T
M_CAP	Benign	0.0055	T
MetaRNN	Benign	0.057	T
MetaSVM	Benign	-0.92	T
MutationAssessor	Benign	0.55	N
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.22	T
PROVEAN	Uncertain	-2.5	D
REVEL	Benign	0.052
Sift	Uncertain	0.010	D
Sift4G	Uncertain	0.0080	D
Polyphen		0.049	B
Vest4		0.27
MutPred		0.21		Gain of sheet (P = 0.0073);
MVP		0.040
ClinPred		0.15	T
GERP RS		-0.42
Varity_R		0.11
gMVP		0.021

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: rs1427596177; hg19: chr6-26107714;