learning difficulties

Perrault Syndrome

Clinical Characteristics
Ocular Features: 

Nystagmus and limited extraocular movements are usually present in PRLTS1.  Optic atrophy and poor visual acuity have been reported. Ptosis may be present.  The clinical manifestations are variable among and within the types.  Rod dysfunction and ‘retinal atrophy’ were reported in one patient.  The majority of patients have had only limited ocular evaluations.

Systemic Features: 

This is a sex-influenced condition in which both sexes have a sensorineural hearing deficit and neurodegenerative disease (both central and peripheral) but only the females have gonadal dysgenesis.  Motor development is often delayed and ataxia along with a peripheral sensory neuropathy and a variable degree of limb weakness can be present.  Learning difficulties, cognitive decline, and frank mental retardation are frequently described.  The cerebellum may be atrophic.

There is considerable variability in the clinical signs.

Genetics

The combination of hearing loss in males and females, ovarian dysgenesis in females, and variable neurologic signs including external ophthalmoplegia and sometimes optic atrophy is known as Perrault syndrome.  The ocular movement abnormalities are seen primarily in PRLTS1. 

At least 5 unique mutations have been found accounting for types PRLTS1-5.  PRLTS1 (233400) results from mutations in HSD17B4 (5q23.1), type PRLTS2 (614926) is caused by mutations in the HARS2 gene, PPRLTS3 (614129) by mutations in the CLPP gene, PRLTS4 (615300) by mutations in the LARS2 gene, and PRLTS5 (616138) by mutations in C10orf2 (listed in this database as External Ophthalmoplegia, C10orf2, and mtDNA mutations,.

The inheritance pattern among different types may be autosomal recessive or autosomal dominant.

Pedigree: 
Autosomal dominant
Autosomal recessive
Treatment
Treatment Options: 

No effective treatment is known.

References
Article Title: 

Perrault syndrome: further evidence for genetic heterogeneity

Jenkinson EM, Clayton-Smith J, Mehta S, Bennett C, Reardon W, Green A, Pearce SH, De Michele G, Conway GS, Cilliers D, Moreton N, Davis JR, Trump D, Newman WG. Perrault syndrome: further evidence for genetic heterogeneity. J Neurol. 2012 May;259(5):974-6.

PubMed ID: 
22037954

Perrault syndrome in sisters

McCarthy DJ, Opitz JM. Perrault syndrome in sisters. Am J Med Genet. 1985 Nov;22(3):629-31.

PubMed ID: 
4061497
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