Cerebral dysgenesis, neuropathy, ichthyosis, and palmoplantar keratoderma syndrome

Alternate names

CEDNIK syndrome

Definition

CEDNIK syndrome is a neurocutaneaous syndrome characterized by severe developmental abnormalities of the nervous system and aberrant differentiation of the epidermis.

Epidemiology

It has been described so far in seven affected individuals (four boys and three girls) from two consanguineous families.

Cause

It is caused by mutations in the SNAP29 gene (22q11.2) which encodes a SNARE protein involved in vesicle fusion.

Inheritance

Autosomal recessive inheritance, a 25% chance

The disease is inherited as an autosomal recessive condition.

Signs and symptoms

Clinically, the patients display a unique constellation of clinical signs described with the acronym CEDNIK: CErebral Dysgenesis, Neuropathy, Ichthyosis, and palmoplantar Keratoderma.

For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. 80%-99% of people have these symptoms

• Ataxia
• Diffuse palmoplantar keratoderma
• Downslanted palpebral fissures(Downward slanting of the opening between the eyelids)
• Global developmental delay
• Hypertelorism(Wide-set eyes)
• Ichthyosis
• Intellectual disability(Mental deficiency)
• Long face(Elongation of face)
• Microcephaly(Abnormally small skull)
• Poor head control
• Prominent nasal bridge(Elevated nasal bridge)

30%-79% of people have these symptoms

• Abnormal corpus callosum morphology
• Abnormality of eye movement(Abnormal eye movement)
• Abnormality of peripheral nerve conduction
• Areflexia(Absent tendon reflexes)
• Optic atrophy
• Pachygyria(Fewer and broader ridges in brain)
• Peripheral neuropathy
• Polymicrogyria(More grooves in brain)

5%-29% of people have these symptoms

• Abnormality of the dentition(Abnormal dentition)
• Abnormality of vision(Abnormality of sight)
• Congestive heart failure(Cardiac failure)
• Depressed nasal ridge(Flat nose)
• Dolichocephaly(Long, narrow head)
• Hypogonadism(Decreased activity of gonads)
• Macrotia(Large ears)
• Nephrotic syndrome
• Proteinuria(High urine protein levels)
• Seizure
• Sensorineural hearing impairment
• Short stature(Decreased body height)
• Stroke

Diagnosis

• Brain magnetic resonance imaging (MRI) shows various degrees of cerebral dysgenesis including absence of corpus callosum and cortical dysplasia.
• Tendon reflexes are usually absent.
• Nerve conduction studies usually show decreased amplitude indicating decrease in the number of active neurons.
• Muscle biopsies show atrophy.
• Ophthalmologic evaluation show hypoplastic optic disk and electrophysiological studies were suggestive of decreased conductance in retina and features of macular atrophy.
• Mild sensorineural hearing loss is present.

NIH genetic and rare disease info

• NIH info on Cerebral dysgenesis, neuropathy, ichthyosis, and palmoplantar keratoderma syndrome

Cerebral dysgenesis, neuropathy, ichthyosis, and palmoplantar keratoderma syndrome is a rare disease.