14-74480037-C-T

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BS1_Supporting

The NM_006432.5(NPC2):c.*237G>A variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000233 in 1,476,594 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 Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00024 (0 hom.)
• Consequence: NPC2 NM_006432.5 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.369

Genes affected

NPC2 (HGNC:14537): (NPC intracellular cholesterol transporter 2) This gene encodes a protein containing a lipid recognition domain. The encoded protein may function in regulating the transport of cholesterol through the late endosomal/lysosomal system. Mutations in this gene have been associated with Niemann-Pick disease, type C2 and frontal lobe atrophy. [provided by RefSeq, Jul 2008]

SYNDIG1L (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.75).
• BS1: Variant frequency is greater than expected in population amr. gnomad4 allele frequency = 0.000204 (31/152186) while in subpopulation AMR AF= 0.000981 (15/15294). AF 95% confidence interval is 0.000604. There are 0 homozygotes in gnomad4. There are 13 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NPC2	NM_006432.5	c.*237G>A		3_prime_UTR_variant	5/5	ENST00000555619.6
SYNDIG1L	XM_017021600.2	c.-5791G>A		5_prime_UTR_variant	1/4
NPC2	NM_001363688.1	c.*581G>A		3_prime_UTR_variant	4/4
NPC2	NM_001375440.1	c.*237G>A		3_prime_UTR_variant	4/4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NPC2	ENST00000555619.6	c.*237G>A		3_prime_UTR_variant	5/5	1	NM_006432.5	P4

Frequencies

GnomAD3 genomes AF: 0.000204 AC: 31 AN: 152068 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000242

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000982

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000176

Gnomad OTH AF: 0.00143

GnomAD3 exomes AF: 0.000194 AC: 20 AN: 103250 Hom.: 0 AF XY: 0.000196 AC XY: 11 AN XY: 56232

Gnomad AFR exome AF: 0.000169

Gnomad AMR exome AF: 0.000436

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000211

Gnomad OTH exome AF: 0.000968

GnomAD4 exome AF: 0.000236 AC: 313 AN: 1324408 Hom.: 0 Cov.: 31 AF XY: 0.000239 AC XY: 155 AN XY: 649040

Gnomad4 AFR exome AF: 0.0000696

Gnomad4 AMR exome AF: 0.000672

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000701

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000248

Gnomad4 OTH exome AF: 0.000438

GnomAD4 genome AF: 0.000204 AC: 31 AN: 152186 Hom.: 0 Cov.: 32 AF XY: 0.000175 AC XY: 13 AN XY: 74410

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.000981

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000176

Gnomad4 OTH AF: 0.00142

Alfa AF: 0.000285 Hom.: 0

Bravo AF: 0.000461

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Niemann-Pick disease, type C1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.75
Cadd	Benign	6.7
Dann	Benign	0.63
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

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: rs185533644; hg19: chr14-74946740;