chr8-144333966-G-A

Position:

• chr8-144333966-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_031309.6(SCRT1):​c.266C>T​(p.Thr89Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000331 in 1,209,648 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 10/17 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000033 (0 hom.)
• Consequence: SCRT1 NM_031309.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.14

Genes affected

SCRT1 (HGNC:15950): (scratch family transcriptional repressor 1) This gene encodes a C2H2-type zinc finger transcriptional repressor that binds to E-box motifs. The encoded protein may promote neural differention and may be involved in cancers with neuroendocrine features. [provided by RefSeq, Jul 2013]

SLC52A2 (HGNC:30224): (solute carrier family 52 member 2) This gene encodes a membrane protein which belongs to the riboflavin transporter family. In humans, riboflavin must be obtained by intestinal absorption because it cannot be synthesized by the body. The water-soluble vitamin riboflavin is processed to the coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) which then act as intermediaries in many cellular metabolic reactions. Paralogous members of the riboflavin transporter gene family are located on chromosomes 17 and 20. Unlike other members of this family, this gene has higher expression in brain tissue than small intestine. Alternative splicing of this gene results in multiple transcript variants encoding the same protein. Mutations in this gene have been associated with Brown-Vialetto-Van Laere syndrome 2 - an autosomal recessive progressive neurologic disorder characterized by deafness, bulbar dysfunction, and axial and limb hypotonia. [provided by RefSeq, Jul 2012]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.14109385).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCRT1	NM_031309.6	c.266C>T	p.Thr89Ile	missense_variant	2/2	ENST00000569446.3	NP_112599.2
SCRT1	XM_024447291.2	c.65C>T	p.Thr22Ile	missense_variant	2/2		XP_024303059.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCRT1	ENST00000569446.3	c.266C>T	p.Thr89Ile	missense_variant	2/2	1	NM_031309.6	ENSP00000455711	P1
SLC52A2	ENST00000675888.1	c.-256G>A		5_prime_UTR_variant	1/5			ENSP00000502294	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000331 AC: 4 AN: 1209648 Hom.: 0 Cov.: 32 AF XY: 0.00000342 AC XY: 2 AN XY: 585540

Gnomad4 AFR exome AF: 0.0000845

Gnomad4 AMR exome AF: 0.0000852

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: 0.00000101

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

Bravo AF: 0.0000151

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 25, 2023

The c.266C>T (p.T89I) alteration is located in exon 2 (coding exon 2) of the SCRT1 gene. This alteration results from a C to T substitution at nucleotide position 266, causing the threonine (T) at amino acid position 89 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.23
BayesDel_addAF	Benign	-0.23	T
BayesDel_noAF	Benign	-0.57
CADD	Uncertain	26
DANN	Benign	0.92
Eigen	Benign	-0.72
Eigen_PC	Benign	-0.78
FATHMM_MKL	Benign	0.59	D
M_CAP	Uncertain	0.17	D
MetaRNN	Benign	0.14	T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	0.93	N
PrimateAI	Pathogenic	0.95	D
PROVEAN	Benign	-1.6	N
Sift	Benign	0.039	D
Sift4G	Benign	0.072	T
Vest4		0.17
MutPred		0.28		Loss of glycosylation at T89 (P = 0);
MVP		0.030
ClinPred		0.80	D
GERP RS		1.8
gMVP		0.39

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: rs1377236647; hg19: chr8-145557628;