Features include always present findings: Parietal bossing, Hypoplastic scapulae, Tapered finger, and Aplasia/Hypoplasia of the hallux and others; and very common findings: Large fontanelles, Proptosis, Short upper lip, and Aplasia/Hypoplasia of the middle phalanges of the hand and others. 100 total HPO annotations.

FIG4 encodes FIG4 phosphoinositide 5-phosphatase (907 aa). Dual specificity phosphatase component of the PI(3,5)P2 regulatory complex which regulates both the synthesis and turnover of phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2). Highest expression in Artery Tibial (25.0 TPM) and Brain Frontal Cortex BA9 (22.9 TPM).

Yunis-Varon syndrome is associated with mutations in the FIG4 gene on chromosome 6.

FIG4 is classified as a druggable target with score 0.0.

Genetic testing for FIG4 is available. Testing is considered confirmatory for diagnosis.

Phenotype severity distribution: 23 always present features, 14 very common features, 42 common features.

Estimated prevalence: <1 in 1,000,000 (VERY_RARE).

No clinical trials have been registered for Yunis-Varon syndrome.

4 publications have been identified in PubMed for Yunis-Varon syndrome. Research spans Review / Meta-Analysis (50%) and Basic Science / Preclinical (50%).

Recent Publications

• Lauerova B (2025). [PMID: 41177402](https://pubmed.ncbi.nlm.nih.gov/41177402/). *European journal of medical genetics*. [Review / Meta-Analysis]

• Tang H (2025). [PMID: 40860339](https://pubmed.ncbi.nlm.nih.gov/40860339/). *Frontiers in genetics*. [Basic Science / Preclinical]

• Hatton CL (2025). [PMID: 40798926](https://pubmed.ncbi.nlm.nih.gov/40798926/). *Journal of the peripheral nervous system : JPNS*. [Basic Science / Preclinical]

• Boura I (2024). [PMID: 39457468](https://pubmed.ncbi.nlm.nih.gov/39457468/). *Genes*. [Review / Meta-Analysis]