Epileptic Encephalopathy, Early Infantile 28

Clinical Characteristics
Ocular Features: 

Infants with this lethal neuropathy often have minimal or absent eye contact from birth.  Responses to visual stimuli are often but not always absent.  Optic atrophy may be present and the ERG is abnormal in some individuals. The retinas may have "abnormal" pigmentation while scotopic and photopic flash ERG responses are reduced as are visual evoked potentials indicating delayed visual maturation with severe macular and optic nerve dysfunction. 

Systemic Features: 

Seizures begin within weeks after birth and are resistant to pharmacological treatment.  There is no spontaneous motility and little or no psychomotor development.  Normal developmental milestones are usually not achieved.  Spasticity and hyperreflexia are often present but some newborn infants are hypotonic.  MRI imaging reveals cortical atrophy with hippocampal hypoplasia and a hypoplastic corpus callosum. Progressive microcephaly has been described.

Infants generally do not live beyond two years of age and may die within weeks or a few months. Pulmonary dysfunction can be a significant cause of morbidity. 

Genetics

The transmission pattern is consistent with autosomal recessive inheritance.  Homozygous and compound heterozygous mutations in the WWOX gene (16q23) have been found in several families.

Among the limited number of patients reported, at least two with compound heterozygous mutations had normal brain imaging, appropriate visual responses, and some ability to interact with their environment.  Profound psychomotor delays, however, remained.  Hypotonia replaced spasticity as a neurological feature in some infants.

The same gene is mutated in autosomal recessive spinocerebellar ataxia 12 (614322), a less severe condition in which gaze-evoked nystagmus occurs.

Other forms of epileptic encephalopathy have been reported (see 617105, 617106, and 617113) including Early Onset Epileptic Encephalopathy 48 (617276).  For an autosomal dominant form of epileptic encephalopathy in this database, see Epileptic Encephalopathy, Early Onset 47 (617166).

 

Treatment
Treatment Options: 

No treatment is known for this condition.

References
Article Title: 

WWOX-related encephalopathies: delineation of the phenotypical spectrum and emerging genotype-phenotype correlation

Mignot C, Lambert L, Pasquier L, Bienvenu T, Delahaye-Duriez A, Keren B, Lefranc J, Saunier A, Allou L, Roth V, Valduga M, Moustaine A, Auvin S, Barrey C, Chantot-Bastaraud S, Lebrun N, Moutard ML, Nougues MC, Vermersch AI, Heron B, Pipiras E, Heron D, Olivier-Faivre L, Gueant JL, Jonveaux P, Philippe C. WWOX-related encephalopathies: delineation of the phenotypical spectrum and emerging genotype-phenotype correlation. J Med Genet. 2015 Jan;52(1):61-70..

PubMed ID: 
25411445

References

Mignot C, Lambert L, Pasquier L, Bienvenu T, Delahaye-Duriez A, Keren B, Lefranc J, Saunier A, Allou L, Roth V, Valduga M, Moustaine A, Auvin S, Barrey C, Chantot-Bastaraud S, Lebrun N, Moutard ML, Nougues MC, Vermersch AI, Heron B, Pipiras E, Heron D, Olivier-Faivre L, Gueant JL, Jonveaux P, Philippe C. WWOX-related encephalopathies: delineation of the phenotypical spectrum and emerging genotype-phenotype correlation. J Med Genet. 2015 Jan;52(1):61-70..

PubMedID: 25411445

Abdel-Salam G, Thoenes M, Afifi HH, Korber F, Swan D, Bolz HJ. The supposed tumor suppressor gene WWOX is mutated in an early lethal microcephaly syndrome with epilepsy, growth retardation and retinal degeneration. Orphanet J Rare Dis. 2014 Jan 23;9:12..

PubMedID: 24456803