NM_020458.4:c.27C>T

Variant names:

• chr2-46941568-C-T
• rs1572670688
• NM_020458.4:c.27C>T

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 2P and 11B. PM2 BP4_Moderate BP6_Very_Strong BP7

The NM_020458.4(TTC7A):​c.27C>T​(p.Ser9Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000214 in 1,404,796 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: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: TTC7A NM_020458.4 synonymous
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:2
• Conservation: PhyloP100: 0.689

Genes affected

TTC7A (HGNC:19750): (tetratricopeptide repeat domain 7A) This gene encodes a protein containing tetratricopeptide repeats. Mutations in this gene disrupt intestinal development and can cause early onset inflammatory bowel disease and intestinal atresia. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jun 2014]

MCFD2 (HGNC:18451): (multiple coagulation factor deficiency 2, ER cargo receptor complex subunit) This gene encodes a soluble luminal protein with two calmodulin-like EF-hand motifs at its C-terminus. This protein forms a complex with LMAN1 (lectin mannose binding protein 1; also known as ERGIC-53) that facilitates the transport of coagulation factors V (FV) and VIII (FVIII) from the endoplasmic reticulum to the Golgi apparatus via an endoplasmic reticulum Golgi intermediate compartment (ERGIC). Mutations in this gene cause combined deficiency of FV and FVIII (F5F8D); a rare autosomal recessive bleeding disorder characterized by mild to moderate bleeding and coordinate reduction in plasma FV and FVIII levels. This protein has also been shown to maintain stem cell potential in adult central nervous system and is a marker for testicular germ cell tumors. The 3' UTR of this gene contains a transposon-like human repeat element named 'THE 1'. A processed RNA pseudogene of this gene is on chromosome 6p22.1. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Apr 2016]

ACMG classification

Verdict is Benign. Variant got -9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.23).
• BP6: Variant 2-46941568-C-T is Benign according to our data. Variant chr2-46941568-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 808739.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=0.689 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTC7A	NM_020458.4	c.27C>T	p.Ser9Ser	synonymous_variant	Exon 1 of 20	ENST00000319190.11	NP_065191.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTC7A	ENST00000319190.11	c.27C>T	p.Ser9Ser	synonymous_variant	Exon 1 of 20	2	NM_020458.4	ENSP00000316699.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000214 AC: 3 AN: 1404796 Hom.: 0 Cov.: 31 AF XY: 0.00000433 AC XY: 3 AN XY: 693582

Gnomad4 AFR exome AF: 0.0000313

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: 9.23e-7

Gnomad4 OTH exome AF: 0.0000172

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely benign

Submissions summary: Benign:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Benign:1

Dec 01, 2023

CeGaT Center for Human Genetics Tuebingen

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

TTC7A: PM2:Supporting, BP4, BP7 -

Multiple gastrointestinal atresias Benign:1

Jul 12, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.23
CADD	Benign	17
DANN	Benign	0.97

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

Publications

LitVar

Other links and lift over

dbSNP: rs1572670688; hg19: chr2-47168707;