17-4899455-C-G

Variant names:

• chr17-4899455-C-G
• rs765913515
• ENST00000521575.1:c.-308C>G

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 2P and 6B. PM2 BP4_Strong BP6_Moderate

The NM_000080.4(CHRNE):​c.1032+13G>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000141 in 1,421,622 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 Likely benign (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: CHRNE NM_000080.4 intron
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.404
• Publications: 0 publications found

Genes affected

C17orf107 (HGNC:37238): (chromosome 17 open reading frame 107)

CHRNE (HGNC:1966): (cholinergic receptor nicotinic epsilon subunit) Acetylcholine receptors at mature mammalian neuromuscular junctions are pentameric protein complexes composed of four subunits in the ratio of two alpha subunits to one beta, one epsilon, and one delta subunit. The acetylcholine receptor changes subunit composition shortly after birth when the epsilon subunit replaces the gamma subunit seen in embryonic receptors. Mutations in the epsilon subunit are associated with congenital myasthenic syndrome. [provided by RefSeq, Sep 2009]

CHRNE Gene-Disease associations (from GenCC):

• congenital myasthenic syndrome

  Inheritance: AR Classification: DEFINITIVE Submitted by: Illumina
• congenital myasthenic syndrome 4A

  Inheritance: AD, AR Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia
• congenital myasthenic syndrome 4B

  Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia
• congenital myasthenic syndrome 4C

  Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp
• postsynaptic congenital myasthenic syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

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 (BayesDel_noAF=-0.8).
• BP6: Variant 17-4899455-C-G is Benign according to our data. Variant chr17-4899455-C-G is described in ClinVar as [Likely_benign]. Clinvar id is 2723044.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNE	NM_000080.4	c.1032+13G>C		intron_variant	Intron 9 of 11	ENST00000649488.2	NP_000071.1
C17orf107	NM_001145536.2	c.-308C>G		upstream_gene_variant		ENST00000381365.4	NP_001139008.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRNE	ENST00000649488.2	c.1032+13G>C		intron_variant	Intron 9 of 11		NM_000080.4	ENSP00000497829.1
C17orf107	ENST00000381365.4	c.-308C>G		upstream_gene_variant		2	NM_001145536.2	ENSP00000370770.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000543 AC: 1 AN: 184198 AF XY: 0.0000100

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.000116

Gnomad EAS 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: 0.00000141 AC: 2 AN: 1421622 Hom.: 0 Cov.: 34 AF XY: 0.00000284 AC XY: 2 AN XY: 703570

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 32924

American (AMR) AF: 0.00 AC: 0 AN: 38276

Ashkenazi Jewish (ASJ) AF: 0.0000395 AC: 1 AN: 25294

East Asian (EAS) AF: 0.00 AC: 0 AN: 37994

South Asian (SAS) AF: 0.00 AC: 0 AN: 81098

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 48786

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5224

European-Non Finnish (NFE) AF: 9.15e-7 AC: 1 AN: 1093096

Other (OTH) AF: 0.00 AC: 0 AN: 58930

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.029673), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital myasthenic syndrome 4A Benign:1

Feb 06, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.80
CADD	Benign	0.087
DANN	Benign	0.43
PhyloP100		-0.40
PromoterAI		-0.10	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs765913515; hg19: chr17-4802750;