rs121909508

Variant names:

• chr2-232526664-T-C
• rs121909508
• NM_000751.3:c.188T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM2 PP3_Strong PP5

The NM_000751.3(CHRND):​c.188T>C​(p.Leu63Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L63I) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: CHRND NM_000751.3 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 7.92
• Publications: 4 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: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• congenital myasthenic syndrome 3B

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

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

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

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99
• PP5: Variant 2-232526664-T-C is Pathogenic according to our data. Variant chr2-232526664-T-C is described in ClinVar as Pathogenic. ClinVar VariationId is 18371.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000751.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHRND	NM_000751.3	MANE Select	c.188T>C	p.Leu63Pro	missense	Exon 2 of 12	NP_000742.1	Q07001-1
	CHRND	NM_001256657.2		c.188T>C	p.Leu63Pro	missense	Exon 2 of 11	NP_001243586.1	Q07001-2
	CHRND	NM_001311196.2		c.-84T>C		5_prime_UTR	Exon 2 of 12	NP_001298125.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHRND	ENST00000258385.8	TSL:1 MANE Select	c.188T>C	p.Leu63Pro	missense	Exon 2 of 12	ENSP00000258385.3	Q07001-1
	CHRND	ENST00000543200.5	TSL:2	c.188T>C	p.Leu63Pro	missense	Exon 2 of 11	ENSP00000438380.1	Q07001-2
	CHRND	ENST00000955151.1		c.188T>C	p.Leu63Pro	missense	Exon 2 of 11	ENSP00000625210.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

Alfa AF: 0.000306 Hom.: 0

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
1	-	-	Congenital myasthenic syndrome 3B (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.47
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.78	D
Eigen	Pathogenic	0.81
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.93	D
M_CAP	Pathogenic	0.36	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.87	D
MutationAssessor	Pathogenic	4.1	H
PhyloP100		7.9
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-6.7	D
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.98		Loss of stability (P = 0.0131)
MVP		1.0
MPC		1.1
ClinPred		1.0	D
GERP RS		4.7
Varity_R		0.99
gMVP		0.96
Mutation Taster		=1/99	disease causing (ClinVar)

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: rs121909508; hg19: chr2-233391374;