Is DDHD1 p.His74= (c.222C>T) pathogenic?

DDHD1 p.His74= (c.222C>T) is classified Likely benign in DDHD1 (ClinVar, Single submitter, 1 submitter; last evaluated 2025-01-24). Absent from gnomAD v4.1; Associated with hereditary spastic paraplegia 28.

What condition is associated with DDHD1 p.His74= (c.222C>T)?

DDHD1 p.His74= (c.222C>T) is associated with hereditary spastic paraplegia 28 (ClinVar).

How common is DDHD1 p.His74= (c.222C>T) in the general population?

DDHD1 p.His74= (c.222C>T) is absent from gnomAD v4.1 (gnomAD).

How is Autosomal recessive spastic paraplegia type 28 inherited?

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

DDHD1 p.His74=

c.222C>T · rs2503574198 · VCV2703837

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Absent

absent from gnomAD v4.1

Conditions

hereditary spastic paraplegia 28

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 0.72	GERP 0.52, phastCons 0.011
Overall
CADD	10.52	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: DDHD1
Protein: p.His74=
Coding: c.222C>T
MANE Select: NM_001160148
dbSNP: rs2503574198
Type: single nucleotide variant
Location: chr14:53152877 (GRCh38)
Gene constraint: LOEUF 0.642 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 67.11

Full DDHD1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

hereditary spastic paraplegia 28 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Autosomal recessive spastic paraplegia type 28 (Orphanet):

Inheritance: Autosomal recessive
Onset: Adolescent, Childhood, Infancy

Similar variants

DDHD1 p.Ala193Val Uncertain significance ★★ ⚠ same condition
DDHD1 p.Ala94Pro Uncertain significance ★★ ⚠ same condition
DDHD1 p.Arg204Trp Uncertain significance ★★ ⚠ same condition
DDHD1 p.Arg288His Uncertain significance ★★ ⚠ same condition
DDHD1 p.Arg554Gln Uncertain significance ★★ ⚠ same condition
DDHD1 p.Arg570Gln Uncertain significance ★★ ⚠ same condition
DDHD1 p.Arg588Gln Uncertain significance ★★ ⚠ same condition
DDHD1 p.Arg596Gln 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/ddhd1-p-his74 (accessed [today's date]).

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