X-153726023-C-T

Position:

• chrX-153726023-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_000033.4(ABCD1):​c.757C>T​(p.Leu253Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000917 in 1,090,716 control chromosomes in the GnomAD database, with no homozygous occurrence. There are no hemizygote samples in GnomAD. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L253V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 26)
  • Exomes 𝑓: 9.2e-7 (0 hom. 0 hem.)
• Consequence: ABCD1 NM_000033.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.23

Genes affected

ABCD1 (HGNC:61): (ATP binding cassette subfamily D member 1) 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. This peroxisomal membrane protein is likely involved in the peroxisomal transport or catabolism of very long chain fatty acids. Defects in this gene have been identified as the underlying cause of adrenoleukodystrophy, an X-chromosome recessively inherited demyelinating disorder of the nervous system. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 8 uncertain in NM_000033.4
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ABCD1	NM_000033.4	c.757C>T	p.Leu253Phe	missense_variant	1/10	ENST00000218104.6
ABCD1	XM_047441916.1	c.757C>T	p.Leu253Phe	missense_variant	1/11
ABCD1	XM_047441917.1	c.757C>T	p.Leu253Phe	missense_variant	1/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ABCD1	ENST00000218104.6	c.757C>T	p.Leu253Phe	missense_variant	1/10	1	NM_000033.4	P1
ABCD1	ENST00000370129.4	c.202C>T	p.Leu68Phe	missense_variant	1/2	2

Frequencies

GnomAD3 genomes Cov.: 26

GnomAD4 exome AF: 9.17e-7 AC: 1 AN: 1090716 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 357752

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: 0.00000119

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 26

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Apr 23, 2024

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis indicates that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.087
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Uncertain	0.010
CADD	Benign	19
DANN	Benign	0.92
DEOGEN2	Pathogenic	0.92	D;D
FATHMM_MKL	Benign	0.52	D
LIST_S2	Benign	0.79	T;T
M_CAP	Pathogenic	0.36	D
MetaRNN	Uncertain	0.53	D;D
MetaSVM	Uncertain	0.25	D
MutationAssessor	Benign	0.91	L;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.79	T
PROVEAN	Benign	-2.1	N;N
REVEL	Uncertain	0.55
Sift	Benign	0.048	D;T
Sift4G	Benign	0.089	T;T
Polyphen		0.045	B;.
Vest4		0.33
MutPred		0.58		Loss of MoRF binding (P = 0.2207);.;
MVP		0.98
MPC		0.67
ClinPred		0.24	T
GERP RS		5.4
Varity_R		0.25
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: rs150151955; hg19: chrX-152991478;