PTDSS1

Chr 8

phosphatidylserine synthase 1

Also known as: LMHD, PSS1, PSSA

NCBI Gene: 9791 ENSG00000156471 UniProt: P48651

This enzyme catalyzes the formation of phosphatidylserine from phosphatidylcholine or phosphatidylethanolamine through a base-exchange reaction, producing a critical membrane phospholipid involved in cellular structure and signaling. Mutations cause Lenz-Majewski hyperostotic dwarfism, a rare disorder characterized by skeletal abnormalities and overgrowth, with autosomal dominant inheritance. The gene is highly constrained against loss-of-function variants (LOEUF 0.448), indicating it is intolerant to complete protein loss.

GeneReviews ResearchSummary from RefSeq, OMIM, UniProt

The protein encoded by this gene catalyzes the formation of phosphatidylserine from either phosphatidylcholine or phosphatidylethanolamine. Phosphatidylserine localizes to the mitochondria-associated membrane of the endoplasmic reticulum, where it serves a structural role as well as a signaling role. Defects in this gene are a cause of Lenz-Majewski hyperostotic dwarfism. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Mar 2014]

GeneReviews ResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

UniProtLenz-Majewski hyperostotic dwarfism

Clinical highlights

Interpreting a novel variant

Gain of function is the curated mechanism (Gene2Phenotype), so a variant that simply removes the protein may not be the pathogenic class here — missense variants in functional domains often carry more weight.Curated gene-level mechanism — a prior for triage, not a per-variant call.

Active trials

Pubs (1 yr)

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P/LP submissions

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P/LP missense

0.45

LOEUF

GOF

Mechanism· G2P

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GeneReview available — PTDSS1