Heimler syndrome

Heimler syndrome
Autosomal recessive pattern is the inheritance manner of this condition
CausesMutations in the PEX1 or PEX6 genes

Heimler syndrome is a rare autosomal recessive condition characterized by sensorineural hearing loss, amelogenesis imperfecta, nail abnormalities and occasional or late-onset retinal pigmentation

Signs and symptoms

a-b) AI affecting the primary and secondary dentitions with a generalised reduced enamel, particularly evident in the lower left permanent first molar tooth (white arrow) c–e) The phenotype of the right eye. c) Fundus image showing pigmentary maculopathy d) Optical coherence tomography showing depletion of photoreceptors in the perifovea e) Fundus autofluorescence

This condition is characterised by the following clinical presentation:[1]

  • Sensorineural hearing loss
  • Enamel hypoplasia of the secondary dentition
  • Nail abnormalities
  • Occasional or
    late-onset retinal pigmentation abnormalities.
  • Amelogenesis imperfecta
  • Leukonychia

Genetics

This condition is caused by mutations in peroxisomal biogenesis factor 1 (PEX1) or peroxisomal biogenesis factor 6 (PEX6) genes.[2] 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.

Differential diagnosis

None has been reported to date.

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 prevelence are not known but it appears be to be < 1/106

History

This condition was first described in 1991.[3]

References

  1. ↑ "Heimler syndrome 1 - Conditions - GTR - NCBI". www.ncbi.nlm.nih.gov. Archived from the original on 28 August 2021. Retrieved 27 August 2021.
  2. ↑ 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
  3. ↑ 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
Classification
This article is issued from Offline. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.