Connexion

GENATLAS PHENOTYPE

last update : 05-12-2016

Symbol	SNELS
Location	9q34.2
Name	subacute necrotizing encephalopathy Leigh syndrome
Corresponding gene	SURF1
Other symbol(s)	SURF1
Main clinical features	lactate acidosis, bilaterally symmetrical necrotic lesions in the brainstem, basal ganglia, thalamus and spinal cord, occuring predominantly in infants , with hypertrichosis, not congenital and mainly distributed on the extremities and forehead, with frequent ataxia, hypotonia and involuntary movements associated with a systemic deficit in cytochrome c oxidase
Genetic determination	mitochondrial
	autosomal recessive
Function/system disorder	mental retardation
Type	disease

Gene product

Name

surfeit 1 (SURF1)

Mechanism(s)

Gene mutation	Chromosome rearrangement	Effect	Comments

insertion-deletion			in exons 1, 4, 6, 8 and 9
various types			most frequent mutations 312-321 del, 311-312 ins AT, 2/3 private mutation
missense			in exons 2, 4, 5, 7 and 8, mutations in splice site of introns 3 and 7, a 18bp deletion in the splice junstion of intron 8 resulting in exon 8 skipping

Remark(s)

SURF1-deficient muscle assessed in the light and electron microscopy panel may be interpreted as normal if COX staining is not employed (PMID: 17908801))

mutations show accumulation of early COX assembly intermediates and marked reduction of the fully assembled complex (Piekutowska-Abramczuk 2009)

Genotype/Phenotype correlations

late onset and mild phenotype, appears to be characteristic of patients carrying at least one SURF1 missense mutation ( PMID: 19780766))