oculomelic amyoplasia

Cranial Dysinnervation Disorders with Strabismus and Arthrogryposis

Clinical Characteristics
Ocular Features: 

Strabismus and/or ophthalmoplegia are important features of a group of conditions known as cranial dysinnervation disorders.  Ptosis, Duane syndrome, V pattern exotropia and various degrees of ophthalmoplegia may be seen.  There may be considerable asymmetry in the manifestations in the two eyes.  Epicanthal folds, blepharophimosis, and hypermetropia are sometimes present.  Some patients have corneal leukomas, keratoglobus, high corneal astigmatism, and dysplastic optic disks. 

A pigmentary retinopathy and folds in the macula with an abnormal ERG has been reported.  Subnormal vision has been reported in some patients.

Systemic Features: 

Patients are often short in stature with pectus excavatum, spine stiffness, highly arched palate, and club feet.  Limited forearm rotation and wrist extension may be present.  The fingers appear long and often have contractures while the palmar and phalangeal creases may be absent.  Camptodactyly and clinodactyly are common.  Deep tendon reflexes are often hyporeactive and decreased muscle mass has been noted.  The muscles seem "firm" to palpation.  Restrictive lung disease has been reported.  Hearing loss is experienced by some individuals.

Genetics

Distal arthrogryposis type 5D is caused by homozygous or compound heterozygous mutations in the ECEL1 gene located at 2q36.  However, a similar phenotype (albeit with more severe ocular manifestations) results from heterozygous mutations in PIEZO2 (18p11).  Heterozygous mutations in the PIEZO2 gene have also been reported to cause distal arthrogryposis type 3 (Gordon syndrome [114300]) and Marden-Walker syndrome (248700) and all of these may be simply phenotypical variations of the same disorder.

Pedigree: 
Autosomal dominant
Autosomal recessive
Treatment
Treatment Options: 

There is no treatment for this condition.  Patients with subnormal vision may benefit from low vision aids and selective surgery may be helpful in reducing the physical restrictions from physical deformities.

References
Article Title: 

Mutations in PIEZO2 cause Gordon syndrome, Marden-Walker syndrome, and distal arthrogryposis type 5

McMillin MJ, Beck AE, Chong JX, Shively KM, Buckingham KJ, Gildersleeve HI, Aracena MI, Aylsworth AS, Bitoun P, Carey JC, Clericuzio CL, Crow YJ, Curry CJ, Devriendt K, Everman DB, Fryer A, Gibson K, Giovannucci Uzielli ML, Graham JM Jr, Hall JG, Hecht JT, Heidenreich RA, Hurst JA, Irani S, Krapels IP, Leroy JG, Mowat D, Plant GT, Robertson SP, Schorry EK, Scott RH, Seaver LH, Sherr E, Splitt M, Stewart H, Stumpel C, Temel SG, Weaver DD, Whiteford M, Williams MS, Tabor HK, Smith JD, Shendure J, Nickerson DA; University of Washington Center for Mendelian Genomics, Bamshad MJ. Mutations in PIEZO2 cause Gordon syndrome, Marden-Walker syndrome, and distal arthrogryposis type 5. Am J Hum Genet. 2014 May 1;94(5):734-44.

PubMed ID: 
24726473
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