Bardet–Biedl syndrome

The Laurence -Moon -Biedl - Bardet syndrome ( LMBBS ) is a congenital and not the cause incurable disability on the basis of an autosomal recessive inherited gene mutation at twelve possible genes. There were once two different syndrome types: Laurence -Moon - Bardet Biedl syndrome and syndrome. International is now divided into types 1-12 depending on which gene is hit. The syndrome belongs to the group of ciliopathies

Frequency of occurrence and origin

The LMBB syndrome is relatively rare. The average probability of occurrence of Bardet Biedl type is between 1:160.000 and 1:15.000, the Laurence -Moon - type is even rarer.

Basis of this disability is a genetic mutation, the relevant loci for Bardet Biedl type are 16q21 and 11q13. What is caused by the mutation is still unclear; could be considered a enzymopathy a disturbance of the hypothalamic-pituitary function or a kinesin defect. About 50 % of children with the syndrome come from incestuous relationships ( family connections).

Heterozygous carriers of the mutation are healthy, for them there is no increased risk of developing typical manifestations of the syndrome such as obesity, diabetes, high blood pressure or kidney disease.

History

The syndrome has been a scientific point first described at different times of John Laurence (1866, Department of Ophthalmology), his colleague Robert Charles Moon ( Subject Ophthalmology), Georges Bardet (beginning of 20th century, Department of General Practice) and Artur Biedl (beginning of 20th century, Department of Endocrinology). 1925, the research has been completed for the time being symptomatology and the disability picture got the name Laurence -Moon - Bardet -Biedl syndrome, which was later shortened to Bardet -Biedl syndrome.

Features

In the field of clinical symptoms is distinguished in the Laurence -Moon syndrome ( without polydactyly and obesity, but with paraplegia and hypotonia ) and the Bardet- Biedl syndrome (with polydactyly, obesity and features of the kidneys). Not all people with this special show all the features and not all features are detectable in equally strong expression; it must be considered in the diagnosis of a strong intrafamilial expressivity. Heaped are in people with this gene mutation determine the following indicators:

  • Face, eyes and ears broadened nasal root
  • Short neck
  • Below-average number of teeth
  • Retinitis pigmentosa, possibly resulting blindness
  • Hemeralopia
  • Downward sloping external canthus
  • Hardness of hearing
  • Comparatively low-lying ears
  • Extremities Polydactyly, often the toes
  • Body Obesity (overweight)
  • Diabetes mellitus
  • Arterial hypertension ( high blood pressure)
  • Dwarfism
  • Hypotonia (muscle weakness)
  • Malformations of ovaries or underdevelopment of the penis ( micropenis ) and scrotum, degeneration of testicular tubules, Leydig cell hypoplasia ( hypogenitalism, hypogonadism )
  • Abnormalities in the field of liver and biliary tract
  • Susceptibility to diseases of the kidneys, often primary renal hypoplasia with pyelonephritis and uremia
  • Others cognitive disability varying severity Straight
  • Disorders of motor
  • Lack of drive
  • Delayed or absent puberty

Treatment and differential diagnosis

The syndrome is not incurable, only the symptoms can be treated. As a differential diagnosis are the Alström syndrome Börjeson - Forssman -Lehmann syndrome in Prader -Willi syndrome, Smith - Lemli -Opitz syndrome and Cohen syndrome question.

Recessive trait Ciliopathy Zygosity#Heterozygous Family medicine Medical diagnosis Nyctalopia Eyelid Congenital disorder Prader–Willi syndrome Digital Object Identifier
104840
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