chr12-39618736-A-G

Position:

• chr12-39618736-A-G

Variant summary

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

The NM_005164.4(ABCD2):​c.880T>C​(p.Tyr294His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,890 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: ABCD2 NM_005164.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.78

Genes affected

ABCD2 (HGNC:66): (ATP binding cassette subfamily D member 2) The protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC) transporters. ABC proteins transport various molecules across extra- and intra-cellular membranes. ABC genes are divided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, White). This protein is a member of the ALD subfamily, which is involved in peroxisomal import of fatty acids and/or fatty acyl-CoAs in the organelle. All known peroxisomal ABC transporters are half transporters which require a partner half transporter molecule to form a functional homodimeric or heterodimeric transporter. The function of this peroxisomal membrane protein is unknown; however this protein is speculated to function as a dimerization partner of ABCD1 and/or other peroxisomal ABC transporters. Mutations in this gene have been observed in patients with adrenoleukodystrophy, a severe demyelinating disease. This gene has been identified as a candidate for a modifier gene, accounting for the extreme variation among adrenoleukodystrophy phenotypes. This gene is also a candidate for a complement group of Zellweger syndrome, a genetically heterogeneous disorder of peroxisomal biogenesis. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ABCD2	NM_005164.4	c.880T>C	p.Tyr294His	missense_variant	1/10	ENST00000308666.4	NP_005155.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ABCD2	ENST00000308666.4	c.880T>C	p.Tyr294His	missense_variant	1/10	1	NM_005164.4	ENSP00000310688	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461890 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727246

Gnomad4 AFR exome AF: 0.00

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: 0.00000719

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

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

Dec 02, 2022

The c.880T>C (p.Y294H) alteration is located in exon 1 (coding exon 1) of the ABCD2 gene. This alteration results from a T to C substitution at nucleotide position 880, causing the tyrosine (Y) at amino acid position 294 to be replaced by a histidine (H). 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	0.29
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Uncertain	0.010
CADD	Benign	22
DANN	Uncertain	0.98
DEOGEN2	Pathogenic	0.91	D
Eigen	Benign	0.14
Eigen_PC	Uncertain	0.32
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Benign	0.044	D
MetaRNN	Uncertain	0.49	T
MetaSVM	Uncertain	-0.022	T
MutationAssessor	Benign	1.5	L
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.77	T
PROVEAN	Benign	-2.3	N
REVEL	Pathogenic	0.65
Sift	Benign	0.36	T
Sift4G	Benign	0.46	T
Polyphen		0.11	B
Vest4		0.40
MutPred		0.75		Gain of disorder (P = 0.022);
MVP		0.90
MPC		0.85
ClinPred		0.83	D
GERP RS		5.5
Varity_R		0.30
gMVP		0.89

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: rs1285092501; hg19: chr12-40012538;