NM_004733.4:c.1425A>T

Variant names:

• chr3-155829745-T-A
• rs777226978
• NM_004733.4:c.1425A>T

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_004733.4(SLC33A1):​c.1425A>T​(p.Thr475Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,852 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. T475T) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SLC33A1 NM_004733.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.167
• Publications: 0 publications found

Genes affected

SLC33A1 (HGNC:95): (solute carrier family 33 member 1) The protein encoded by this gene is required for the formation of O-acetylated (Ac) gangliosides. The encoded protein is predicted to contain 6 to 10 transmembrane domains, and a leucine zipper motif in transmembrane domain III. Defects in this gene have been reported to cause spastic paraplegia autosomal dominant type 42 (SPG42) in one Chinese family, but not in similar patients of European descent. Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jul 2010]

SLC33A1 Gene-Disease associations (from GenCC):

• Huppke-Brendel syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae)
• hereditary spastic paraplegia 42

  Inheritance: AD Classification: SUPPORTIVE, LIMITED Submitted by: Illumina, Orphanet

ENSG00000284952 (HGNC:):

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (REVEL=0.042).
• BP7: Synonymous conserved (PhyloP=0.167 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SLC33A1	NM_004733.4	c.1425A>T	p.Thr475Thr	synonymous_variant	Exon 5 of 6	ENST00000643144.2	NP_004724.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SLC33A1	ENST00000643144.2	c.1425A>T	p.Thr475Thr	synonymous_variant	Exon 5 of 6		NM_004733.4	ENSP00000496241.1
ENSG00000284952	ENST00000643876.1	n.*747A>T		non_coding_transcript_exon_variant	Exon 5 of 10			ENSP00000495323.1
ENSG00000284952	ENST00000643876.1	n.*747A>T		3_prime_UTR_variant	Exon 5 of 10			ENSP00000495323.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461852 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727228

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: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111990

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.60
CADD	Benign	7.4
DANN	Benign	0.66
PhyloP100		0.17
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

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: rs777226978; hg19: chr3-155547534;