Prevalence < 1/106. Deletion located in 6q16.1-6q16.2.

The SIM1, GRIK2, POPDC3, EPHA7 and MCHR2 genes contained in this chromosomal zone are respectively associated with obesity, autism, cardiac abnormalities, and hyperphagia and energy metabolism disorders.

Phenotype similar to Prader-Willi syndrome:

-        obesity,

-        hyperphagia,

-        hypotonia,

-        short hands and feet,

-        vision disorders

-        developmental delay.

In case of deletion of the SIM1 gene, panhypopituitarism may be observed in case of associated deletion of the POU3F2 gene.

Anesthetic implications:

check endocrinological status in case of SIM1 gene mutation -thyroid, growth hormone, ADH, cortisol); see Prader Willi syndrome

References:

-        Traylor RN, Fan Z, Hudson B, Rosenfeld JA, Shaffer LG, Torchia BS, Ballif BC.
Microdeletion of 6q16.1 encompassing EPHA7 in a child with mild neurological abnormalities and dysmorphic features: case report.
Mol Cytogenet. 2009; 2: 17. doi: 10.1186/1755-8166-2-17

Updated: August 2023