ABCD1

Chr XXLR

ATP binding cassette subfamily D member 1

Also known as: ABC42, ALD, ALDP, AMN

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]

Primary Disease Associations & Inheritance

AdrenoleukodystrophyMIM #300100
XLR
Adrenomyeloneuropathy, adultMIM #300100
XLR
277
ClinVar variants
98
Pathogenic / LP
1.00
pLI score· haploinsufficient
6
Active trials
Clinical SummaryABCD1
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Gene-Disease Validity (ClinGen)
adrenoleukodystrophy · XLDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Highly constrained gene — heterozygous loss-of-function variants are very rare in the population (pLI 1.00). One damaged copy is likely sufficient to cause disease.
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ClinVar Variants
98 Pathogenic / Likely Pathogenic· 138 VUS of 277 total submissions
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Clinical Trials
6 active or recruiting trials — potential therapeutic options may be available

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

LoF intolerant — likely haploinsufficient
LoF Constraint?LOEUF (Loss-of-function Observed/Expected Upper bound Fraction) is the upper bound of the 90% CI for LoF OE — the preferred gnomAD v4 metric. Lower = more intolerant to LoF. LOEUF < 0.35 = highly constrained.
0.15LOEUF
pLI 0.999
Z-score 4.13
OE 0.00 (0.000.15)
Highly constrained

Among the most LoF-intolerant genes (~top 3%)

Missense Constraint?Missense Z-score: standard deviations fewer missense variants observed vs. expected. Z > 3.09 (p < 0.001) = gene does not tolerate missense variation. OE missense < 0.6 is also considered constrained.
1.87Z-score
OE missense 0.72 (0.650.80)
250 obs / 347.9 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?Shaded band = 90% confidence interval. Vertical tick = point estimate. Grey threshold line = gnomAD constraint cutoff for that variant class.
LoF OE?Ratio of observed to expected LoF variants. Upper CI bound (LOEUF) ≤ 0.35 = strong LoF constraint signal.0.00 (0.000.15)
00.351.4
Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.72 (0.650.80)
00.61.4
Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.0.96
01.21.6
LoF obs/exp: 0 / 19.9Missense obs/exp: 250 / 347.9Syn Z: 0.44

ClinVar Variant Classifications

277 submitted variants in ClinVar

Classification Summary

Pathogenic59
Likely Pathogenic39
VUS138
Likely Benign39
Conflicting2
59
Pathogenic
39
Likely Pathogenic
138
VUS
39
Likely Benign
2
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
33
2
24
0
59
Likely Pathogenic
12
26
1
0
39
VUS
2
112
18
6
138
Likely Benign
0
3
14
22
39
Benign
0
0
0
0
0
Conflicting
2
Total471435728277

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

ABCD1 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

Gene2Phenotype Curations

ABCD1-related adrenoleukodystrophy

definitive
Monoallelic X HemizygousLoss Of FunctionAbsent Gene Product
Dev. DisordersEyeSkin
G2P ↗

Gene2Phenotype curations · DECIPHER consortium patient cohort (public variants) · deciphergenomics.org

OMIM — Genotype-Phenotype Relationships

1 OMIM entry

Adrenoleukodystrophy

MIM #300100

Molecular basis of disorder known

X-linked recessive

Adrenomyeloneuropathy, adult

MIM #300100

Molecular basis of disorder known

X-linked recessive
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GeneReview available — ABCD1
Authoritative clinical overview · NCBI Bookshelf · Recommended first read
Open GeneReview ↗
Clinical Literature
Landmark / reviewRecent case evidence