pons hypoplasia

Gaze Palsy, Familial Horizontal, with Progressive Scoliosis 2

Clinical Characteristics
Ocular Features: 

Strabismus is present at birth.  Horizontal eye movements are restricted but vertical gaze can be normal.  The optic nerves appear normal.

Systemic Features: 

Hypotonia may be noted at birth but ankle clonus and spasticity can develop later.  Progressive kyphoscoliosis has been diagnosed as early as the age of 4 years and may result in restrictive lung disease requiring spine surgery by the second decade of life.  Developmental milestones such as walking and talking are delayed and intellectual development is subnormal.  Mirror movements may be present.  Gait may be unsteady but can be normal.

Brain MRI reveals a variety of malformations.  Agenesis of the corpus callosum is present and the white matter tracts appear disorganized.  The superior cerebellar peduncles fail to decussate and transverse pontine fibers may be absent.  The pons and midbrain are hypoplastic while there is a midline cleft throughout the brainstem resulting in a butterfly-shaped medulla.


Homozygous mutations in the DCC gene (18q21) are responsible for this condition.  Three patients in 2 unrelated consanguineous families have been reported.  Studies suggest that the DCC gene product is important for forebrain and brainstem midline crossing of neurons.

See Gaze Palsy, Familial Horizontal, with Progressive Scoliosis 1 (607313) for another disorder with somewhat similar features.

Autosomal recessive
Treatment Options: 

No treatment has been reported.

Article Title: 

Biallelic mutations in human DCC cause developmental split-brain syndrome

Jamuar SS, Schmitz-Abe K, D'Gama AM, Drottar M, Chan WM, Peeva M, Servattalab S, Lam AN, Delgado MR, Clegg NJ, Zayed ZA, Dogar MA, Alorainy IA, Jamea AA, Abu-Amero K, Griebel M, Ward W, Lein ES, Markianos K, Barkovich AJ, Robson CD, Grant PE, Bosley TM, Engle EC, Walsh CA, Yu TW. Biallelic mutations in human DCC cause developmental split-brain syndrome. Nat Genet. 2017 Apr;49(4):606-612.

PubMed ID: 
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