NM_000751.3:c.52+1G>T

Variant names:

• chr2-232526268-G-T
• rs2106205676
• NM_000751.3:c.52+1G>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_000751.3(CHRND):​c.52+1G>T variant causes a splice donor, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,258 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CHRND NM_000751.3 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.30
• Publications: 0 publications found

Genes affected

CHRND (HGNC:1965): (cholinergic receptor nicotinic delta subunit) The acetylcholine receptor of muscle has 5 subunits of 4 different types: 2 alpha and 1 each of beta, gamma and delta subunits. After acetylcholine binding, the receptor undergoes an extensive conformation change that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane. Defects in this gene are a cause of multiple pterygium syndrome lethal type (MUPSL), congenital myasthenic syndrome slow-channel type (SCCMS), and congenital myasthenic syndrome fast-channel type (FCCMS). Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2015]

CHRND Gene-Disease associations (from GenCC):

• congenital myasthenic syndrome 3A

  Inheritance: AD Classification: STRONG Submitted by: PanelApp Australia, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• congenital myasthenic syndrome 3B

  Inheritance: AR Classification: STRONG Submitted by: PanelApp Australia, Genomics England PanelApp
• congenital myasthenic syndrome 3C

  Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• lethal multiple pterygium syndrome

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
• postsynaptic congenital myasthenic syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.06949807 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5.9, offset of -7, new splice context is: gcgGTgtgt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRND	NM_000751.3	c.52+1G>T		splice_donor_variant, intron_variant	Intron 1 of 11	ENST00000258385.8	NP_000742.1
CHRND	NM_001256657.2	c.52+1G>T		splice_donor_variant, intron_variant	Intron 1 of 10		NP_001243586.1
CHRND	NM_001311196.2	c.-220+1G>T		splice_donor_variant, intron_variant	Intron 1 of 11		NP_001298125.1
CHRND	NM_001311195.2	c.-220+1G>T		splice_donor_variant, intron_variant	Intron 1 of 9		NP_001298124.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRND	ENST00000258385.8	c.52+1G>T		splice_donor_variant, intron_variant	Intron 1 of 11	1	NM_000751.3	ENSP00000258385.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460258 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 726282

African (AFR) AF: 0.00 AC: 0 AN: 33454

American (AMR) AF: 0.00 AC: 0 AN: 44638

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26062

East Asian (EAS) AF: 0.00 AC: 0 AN: 39692

South Asian (SAS) AF: 0.00 AC: 0 AN: 86118

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53226

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5222

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111576

Other (OTH) AF: 0.00 AC: 0 AN: 60270

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.22
CADD	Pathogenic	31
DANN	Uncertain	0.99
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Benign	0.59	D
PhyloP100		1.3
GERP RS		4.3
PromoterAI		-0.054	Neutral
Mutation Taster		=26/74	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.78		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.78		Position offset: -1

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

Other links and lift over

dbSNP: rs2106205676; hg19: chr2-233390978;