Kenny-Caffey Syndrome, Type 2

Clinical Characteristics
Ocular Features: 

Congenital cataracts have been reported in one patient.  There is a report of pseudopapilledema in a 6 year old and another patient has been described with tortuous and dilated retinal vessels.  The hyperopia is likely the result of the small globes.  In an autopsied patient microscopic calcification was noted in the cornea and the retina.

Systemic Features: 

Hypocalcemia and hyperphosphatemia similar to hypoparathyroidism is seen in individuals with KCS2 but it may be transient and self-limited.  Macrocephaly with short stature is characteristic.  Alopecia, delayed closure of the anterior fontanel, and apparent thickening of the cortex in long bones may be seen.  Males have small testicles but there is no evidence regarding fertility.  In an autopsied case no parathyroid tissue could be identified.  Brain imaging may show calcification in the basal ganglia, dentate nuclei, and parts of the cerebrum and cerebellum.  Intelligence is normal.

Genetics

Several heterozygous mutations in the FAM111A gene (11q12.1) have been found.  Many of these seem to be new mutations but there are a number of published families in which there was transmission from mother to child (of both sexes).

Heterozygous mutations in the same gene are responsible for the autosomal dominant  allelic disorder known as Gracile Bone Dysplasia (602361). 

Treatment
Treatment Options: 

Normalization of serum calcium and phosphorous levels would likely be beneficial but complete correction of all the findings is unlikely.  Removal of congenital cataracts should be considered.

References
Article Title: 

FAM111A mutations result in hypoparathyroidism and impaired skeletal development

Unger S, Gorna MW, Le Bechec A, Do Vale-Pereira S, Bedeschi MF, Geiberger S, Grigelioniene G, Horemuzova E, Lalatta F, Lausch E, Magnani C, Nampoothiri S, Nishimura G, Petrella D, Rojas-Ringeling F, Utsunomiya A, Zabel B, Pradervand S, Harshman K, Campos-Xavier B, Bonafe L, Superti-Furga G, Stevenson B, Superti-Furga A. FAM111A mutations result in hypoparathyroidism and impaired skeletal development. Am J Hum Genet. 2013 Jun 6;92(6):990-5.

PubMed ID: 
23684011

Ocular findings in Kenny's syndrome

Boynton JR, Pheasant TR, Johnson BL, Levin DB, Streeten BW. Ocular findings in Kenny's syndrome. Arch Ophthalmol. 1979 May;97(5):896-900.

PubMed ID: 
444124

References

Unger S, Gorna MW, Le Bechec A, Do Vale-Pereira S, Bedeschi MF, Geiberger S, Grigelioniene G, Horemuzova E, Lalatta F, Lausch E, Magnani C, Nampoothiri S, Nishimura G, Petrella D, Rojas-Ringeling F, Utsunomiya A, Zabel B, Pradervand S, Harshman K, Campos-Xavier B, Bonafe L, Superti-Furga G, Stevenson B, Superti-Furga A. FAM111A mutations result in hypoparathyroidism and impaired skeletal development. Am J Hum Genet. 2013 Jun 6;92(6):990-5.

PubMedID: 23684011

Boynton JR, Pheasant TR, Johnson BL, Levin DB, Streeten BW. Ocular findings in Kenny's syndrome. Arch Ophthalmol. 1979 May;97(5):896-900.

PubMedID: 444124