Heimler syndrome
Heimler syndrome is a rare autosomal recessive condition characterized by sensorineural hearing loss, amelogenesis imperfecta, nail abnormalities and occasional or late-onset retinal pigmentation
Heimler syndrome | |
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Other names | Deafness-enamel hypoplasia-nail defects syndrome |
Autosomal recessive pattern is the inheritance manner of this condition | |
Causes | Mutations in the PEX1 or PEX6 genes |
Signs/symptoms
This condition is characterised by sensorineural hearing loss, enamel hypoplasia of the secondary dentition, nail abnormalities and occasional or late-onset retinal pigmentation abnormalities.
Genetics
This condition is caused by mutations in peroxisomal biogenesis factor 1 (PEX1) or peroxisomal biogenesis factor 6 (PEX6) genes.[1] These gene are involved in peroxisome biogenesis. PEX 1 is located on long arm of chromosome 7 (7q21).2 PEX 6 is located on the short arm of chromosome 6 (6p21). These genes encode AAA+ ATPases. They form part of the mechanism that shuttles the peroxisome targeting signal receptor protein PEX5 back to the cytosol after release of its protein cargo within the peroxisomal lumen.
Diagnosis
The diagnosis is made on clinical grounds and confirmed by gene sequencing.
Treatment
There is no treatment for this condition known at present.
Prognosis
This condition tends to produce only mild abnormalities. Life expectancy is normal.
Epidemiology
This is rare disorder. Precise estimates of its prevalence are not known but it appears be to be < 1/106
History
This condition was first described in 1991.[2]
References
- Ratbi I, Falkenberg KD, Sommen M, Al-Sheqaih N, Guaoua S, Vandeweyer G, Urquhart JE, Chandler KE, Williams SG, Roberts NA, El Alloussi M, Black GC, Ferdinandusse S, Ramdi H, Heimler A, Fryer A, Lynch SA, Cooper N, Ong KR, Smith CE, Inglehearn CF, Mighell AJ, Elcock C, Poulter JA, Tischkowitz M, Davies SJ, Sefiani A, Mironov AA, Newman WG, Waterham HR, Van Camp G (2015) Heimler syndrome is caused by hypomorphic mutations in the peroxisome-biogenesis genes PEX1 and PEX6. Am J Hum Genet 97(4):535-545
- Heimler A, Fox JE, Hershey JE, Crespi P: Sensorineural hearing loss, enamel hypoplasia, and nail abnormalities in sibs. Am J Med Genet 39: 192–195