Is ABCD4 c.668+9C>T pathogenic?

ABCD4 c.668+9C>T is classified Likely benign in ABCD4 (ClinVar, Single submitter, 1 submitter; last evaluated 2025-06-09). Very rare (popmax 0.00667%, afr); Associated with methylmalonic acidemia with homocystinuria, type cblJ.

What condition is associated with ABCD4 c.668+9C>T?

ABCD4 c.668+9C>T is associated with methylmalonic acidemia with homocystinuria, type cblJ (ClinVar).

How common is ABCD4 c.668+9C>T in the general population?

ABCD4 c.668+9C>T is very rare (popmax 0.00667%, afr) (gnomAD).

How is Methylmalonic acidemia with homocystinuria inherited?

Typically Autosomal recessive, X-linked recessive (Orphanet). A genetic counselor can assess individual risk for a family.

ABCD4 c.668+9C>T

VCV4709124

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.00667%, afr)

Conditions

methylmalonic acidemia with homocystinuria, type cblJ

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
Splice region	donor +9	near-intronic (+9 nt from the splice site)
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 0.047	GERP -2.8
Non-coding constraint	Z 2.11	1 kb window · o/e 0.86 · regional · uncalibrated
Overall
CADD	3.418	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00667% African / African-American · 5/74,932 alleles

Filtering AF 0.00255% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00161%

Overall 0.000411% 6/1,461,060 alleles · very rare

Ancestry group	Frequency	1 in
African / African-Americangrpmax	0.00667%	14,986
Remaining individualsnot grpmax-eligible	0.0016%	62,468

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: ABCD4
Coding: c.668+9C>T
MANE Select: NM_005050
Type: single nucleotide variant
Location: chr14:74295845 (GRCh38)
Gene constraint: LOEUF 0.772 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 87.18 · 4 PDB

Full ABCD4 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

methylmalonic acidemia with homocystinuria, type cblJ — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Methylmalonic acidemia with homocystinuria (Orphanet):

Inheritance: Autosomal recessive, X-linked recessive
Onset: All ages

Similar variants

ABCD4 c.542+1G>T Pathogenic ★★ same condition
ABCD4 p.Arg432Gln Likely pathogenic ★★ same condition
ABCD4 p.Asn141Lys Pathogenic/Likely pathogenic ★★ same condition
ABCD4 p.Gln530Ter Pathogenic/Likely pathogenic ★★ same condition
ABCD4 p.Tyr176Ter Pathogenic/Likely pathogenic ★★ same condition
ABCD4 c.1028+5G>A Uncertain significance ★★ same condition
ABCD4 c.425+6C>T Uncertain significance ★★ same condition
ABCD4 c.719+6T>C Uncertain significance ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/abcd4-c-668-plus-9c-t (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown