chr14-74493848-A-T

Variant names:

• chr14-74493848-A-T
• rs2086811553
• NM_194279.4:c.71+3A>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_194279.4(ISCA2):​c.71+3A>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: ISCA2 NM_194279.4 splice_region, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.35
• Publications: 0 publications found

Genes affected

ISCA2 (HGNC:19857): (iron-sulfur cluster assembly 2) The protein encoded by this gene is an A-type iron-sulfur cluster (ISC) protein found in mitochondria. The encoded protein appears to be involved in the maturation of mitochondrial iron-sulfur proteins. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 2012]

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]

NPC2 Gene-Disease associations (from GenCC):

• Niemann-Pick disease, type C2

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Myriad Women’s Health, Labcorp Genetics (formerly Invitae), G2P, Laboratory for Molecular Medicine, Genomics England PanelApp, Ambry Genetics
• Niemann-Pick disease type C, adult neurologic onset

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Niemann-Pick disease type C, juvenile neurologic onset

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Niemann-Pick disease type C, late infantile neurologic onset

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Niemann-Pick disease type C, severe early infantile neurologic onset

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Niemann-Pick disease type C, severe perinatal form

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_194279.4. 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
	ISCA2	NM_194279.4	MANE Select	c.71+3A>T		splice_region intron	N/A	NP_919255.2	Q86U28-1
	ISCA2	NM_001272007.2		c.71+3A>T		splice_region intron	N/A	NP_001258936.1	Q86U28-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ISCA2	ENST00000556816.6	TSL:1 MANE Select	c.71+3A>T		splice_region intron	N/A	ENSP00000452007.1	Q86U28-1
	NPC2	ENST00000556009.5	TSL:5	c.145+183T>A		intron	N/A	ENSP00000450502.1	H0YIZ1
	ISCA2	ENST00000298818.12	TSL:5	c.71+3A>T		splice_region intron	N/A	ENSP00000298818.8	J3QSS7

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1407532 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 695132

African (AFR) AF: 0.00 AC: 0 AN: 32584

American (AMR) AF: 0.00 AC: 0 AN: 35076

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25124

East Asian (EAS) AF: 0.00 AC: 0 AN: 37736

South Asian (SAS) AF: 0.00 AC: 0 AN: 80016

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 49436

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5698

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1083500

Other (OTH) AF: 0.00 AC: 0 AN: 58362

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Multiple mitochondrial dysfunctions syndrome 4 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.53
CADD	Benign	19
DANN	Benign	0.68
PhyloP100		2.3
PromoterAI		0.052	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.80		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.80		Position offset: -3

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs2086811553; hg19: chr14-74960551;