SARDH

Chr 9AR

sarcosine dehydrogenase

Also known as: BPR-2, DMGDHL1, SAR, SARD, SDH

NCBI Gene: 1757 ENSG00000123453 UniProt: Q9UL12

This gene encodes an enzyme localized to the mitochondrial matrix which catalyzes the oxidative demethylation of sarcosine. This enzyme is distinct from another mitochondrial matrix enzyme, dimethylglycine dehydrogenase, which catalyzes a reaction resulting in the formation of sarcosine. Mutations in this gene are associated with sarcosinemia. Alternatively spliced transcript variants have been described. [provided by RefSeq, Oct 2008]

Primary Disease Associations & Inheritance

[Sarcosinemia]MIM #268900

Active trials

Pathogenic / LP

266

ClinVar variants

Pubs (1 yr)

0.7

Missense Z

0.88

LOEUF

Clinical Summary— SARDH

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Gene-Disease Validity (ClinGen)

sarcosinemia · ARLimited

Limited evidence — not for standalone diagnostic reporting

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Population Constraint (gnomAD)

Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

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ClinVar Variants

39 Pathogenic / Likely Pathogenic· 175 VUS of 266 total submissions

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Clinical Trials

1 active or recruiting trial — potential therapeutic options may be available

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GeneReview available — SARDH

Authoritative clinical overview · Recommended first read

Open GeneReview ↗

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

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.

0.88LOEUF

pLI 0.000

Z-score 2.23

OE 0.66 (0.49–0.88)

Tolerant

Typical tolerance to LoF variation

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.

0.68Z-score

OE missense 0.92 (0.86–0.99)

561 obs / 608.1 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.0.66 (0.49–0.88)

0≤0.351.4

Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.92 (0.86–0.99)

0≤0.61.4

Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.0.99

0≤1.21.6

LoF obs/exp: 32 / 48.8Missense obs/exp: 561 / 608.1Syn Z: 0.10

0.6841th %ile

GOF

0.73top 25%

LOF

0.3550th %ile

This gene has evidence for multiple mechanisms of pathogenicity (gain-of-function and dominant-negative). Both the Badonyi & Marsh prediction and the broader genomic evidence point to gain-of-function as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

GOFprediction above median

DNprediction above median

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.