[17] Manipulation of this signaling lipid involves culturing fibroblasts obtained by insertion of ETn2-beta(early transposon 2-beta) into intron 18 of FIG4 gene in vacuolar membrane of mice labeled pale tremor (plt).

[18][19][20] In contrast, homozygous FIG4 defective (FIG4-/-) mice have a reduction of myelin, especially in optic nerves; but this detriment is rescued by an overexpression of human FIG4 I41T at low-level function.

Because this conversion in endosomal membranes changes dynamically with fission and fusion events to create/absorb intracellular transport vesicles, enlarged cytoplasmic vacuoles have been found in patient neurons, muscle, and cartilage.

[27][28] Fluids may also accumulate in a choroid spaces under the retina, causing central serous retinopathy or chorioretinopathy and possibly vision loss.

[29] Paradoxically, overexpression of FIG4 does not yield obvious morphologic phenotype of these fluids accumulating, but alters PI(3,5)P2 levels making cells prone to expansion through dilation of intracellular membranes.

[42] Hypoplasia of frontal lobes, corpus callosum, cerebellar vermis connecting the two brain hemispheres along with polymicrogyria causing excessive folding leading to an abnormally thick cortex are also phenotypes of this disorder.

[43] Obvious signs of Yunis–Varon syndrome include soft and large fontanelles, high forehead, prominent eyes, large ears with hypoplastic lobes, low nasal bridge, anteverted nostrils, short philtrum above the lip, high-arched palate at the roof of the mouth, micrognathia or small jaw, and sparse hair (Hypotrichosis) with absent eyebrows and eyelashes.