10-49651977-C-T

Variant names:

• chr10-49651977-C-T
• rs772695708
• NM_020549.5:c.1605C>T

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 2P and 11B. PM2 BP4_Moderate BP6_Very_Strong BP7

The NM_020549.5(CHAT):​c.1605C>T​(p.Ile535Ile) variant causes a synonymous 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. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: CHAT NM_020549.5 synonymous
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:2
• Conservation: PhyloP100: -0.175
• Publications: 1 publications found

Genes affected

CHAT (HGNC:1912): (choline O-acetyltransferase) This gene encodes an enzyme which catalyzes the biosynthesis of the neurotransmitter acetylcholine. This gene product is a characteristic feature of cholinergic neurons, and changes in these neurons may explain some of the symptoms of Alzheimer's disease. Polymorphisms in this gene have been associated with Alzheimer's disease and mild cognitive impairment. Mutations in this gene are associated with congenital myasthenic syndrome associated with episodic apnea. Multiple transcript variants encoding different isoforms have been found for this gene, and some of these variants have been shown to encode more than one isoform. [provided by RefSeq, May 2010]

CHAT Gene-Disease associations (from GenCC):

• congenital myasthenic syndrome 6

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen
• presynaptic congenital myasthenic syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Benign. The variant received -9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.3).
• BP6: Variant 10-49651977-C-T is Benign according to our data. Variant chr10-49651977-C-T is described in ClinVar as Likely_benign. ClinVar VariationId is 261331.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=-0.175 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020549.5. 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
	CHAT	NM_020549.5	MANE Select	c.1605C>T	p.Ile535Ile	synonymous	Exon 11 of 15	NP_065574.4	P28329-1
	CHAT	NM_001142933.2		c.1359C>T	p.Ile453Ile	synonymous	Exon 12 of 16	NP_001136405.2	P28329-2
	CHAT	NM_001142929.2		c.1251C>T	p.Ile417Ile	synonymous	Exon 11 of 15	NP_001136401.2	P28329-3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHAT	ENST00000337653.7	TSL:1 MANE Select	c.1605C>T	p.Ile535Ile	synonymous	Exon 11 of 15	ENSP00000337103.2	P28329-1
	CHAT	ENST00000395562.2	TSL:1	c.1359C>T	p.Ile453Ile	synonymous	Exon 12 of 16	ENSP00000378929.2	P28329-2
	CHAT	ENST00000339797.5	TSL:1	c.1251C>T	p.Ile417Ile	synonymous	Exon 11 of 15	ENSP00000343486.1	P28329-3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461888 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727244

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1112008

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions

Significance: Likely benign

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	-	1	Familial infantile myasthenia (1)
-	-	1	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.30
CADD	Benign	4.7
DANN	Benign	0.71
PhyloP100		-0.17
Mutation Taster		=93/7	polymorphism

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: rs772695708; hg19: chr10-50860023;