Sjogren-Larsson Syndrome

Question 1

What is the inheritance pattern of Sjogren - Larsson Syndrome?

Answer 1

Autosomal recessive; Fatty aldehyde dehydrogenase (FALDH) gene 17p11.2

The condition is linked to mutations in the FALDH gene, which is located on chromosome 17.

Question 2

What are the prenatal diagnostic methods for Sjogren - Larsson Syndrome?

Answer 2

CVS/amniocentesis with fatty aldehyde dehydrogenase or fatty alcohol oxidoreductase assay; DNA mutation analysis if gene defect is known; fetal skin biopsy at 23 weeks

These methods help identify potential genetic defects before birth.

Question 3

What is the reported incidence of Sjogren - Larsson Syndrome?

Answer 3

More than 200 cases reported, many from northern Sweden

This suggests a possible geographical prevalence.

Question 4

At what age does Sjogren - Larsson Syndrome typically present?

Answer 4

Infancy (ichthyosis); by age 2–3 years old (central nervous system [CNS])

Symptoms often manifest early in life, primarily affecting the skin and CNS.

Question 5

What is the pathogenesis of Sjogren - Larsson Syndrome?

Answer 5

Over 50 mutations in the FALDH gene lead to decreased fatty-alcohol: NAD oxidoreductase (FAO) activity and defective conversion of fatty alcohol to fatty acid

This pathway is crucial for epidermal lipid synthesis and CNS myelin catabolism.

Question 6

What are the key skin features of Sjogren - Larsson Syndrome in infancy?

Answer 6

Generalized ichthyosis with erythroderma, areas of fine scaling, areas of large lamellar scaling, hyperkeratosis, pruritus

Skin symptoms are prominent at an early age.

Question 7

What changes occur in the skin after infancy in Sjogren - Larsson Syndrome?

Answer 7

Generalized darker scale without erythema accentuated in flexures, lower abdomen and back/sides of neck; spares central face

The skin appearance evolves as the child grows.

Question 8

What central nervous system features are associated with Sjogren - Larsson Syndrome?

Answer 8

Mental retardation, spastic di-tetraplegia with scissor gait, speech deficits, epilepsy

CNS involvement can significantly impact development and quality of life.

Question 9

What ocular feature is associated with Sjogren - Larsson Syndrome?

Answer 9

Atypical retinal pigment degeneration in macula—glistening white dots in a peri-macular distribution; retinal pigmentary changes in some patients

Eye symptoms may vary among patients.

Question 10

Name some differential diagnoses for Sjogren - Larsson Syndrome.

Answer 10

• Lamellar ichthyosis
• Congenital ichthyosiform erythroderma
• NLSD
• Multiple sulfatase deficiency

These conditions can present with similar symptoms.

Question 11

What investigations are recommended for Sjogren - Larsson Syndrome?

Answer 11

Enzyme assay in cultured fibroblasts; DNA mutation analysis if defect known

These tests help confirm the diagnosis.

Question 12

What is the management strategy for Sjogren - Larsson Syndrome?

Answer 12

Referral to dermatologist for emolliation and retinoids; referral to neurologist, ophthalmologist, orthopedist; Zileuton inhibits leukotriene B4 synthesis and may help pruritus

A multidisciplinary approach is essential for comprehensive care.

Question 13

What is the prognosis for patients with Sjogren - Larsson Syndrome?

Answer 13

Dependent on severity of CNS complications; if wheelchair-bound and severely retarded, prognosis is guarded; otherwise patients typically live well into adulthood

The prognosis varies significantly based on CNS involvement.