Molekulargenetische Diagnostik
Praxis Dr. Mato Nagel

Laron-Syndrom

Das Laron-Syndrom ist eine autosomal rezessive Erkrankung die durch loss-of-function mutationen im Wachstumshormon-Rezeptor (GHR) Gen hervorgerufen wird.

Klinischer Befund

Klinisch zeichnet sich das Krankheitsbild vor allem durch ein vermindertes Knochenwachstum und eine verzögerte Knochenreifung aus. Dabei sind Knochendysplasien nicht vorhanden.

Labortest

Die typische Laborkonstellation ist ein eher erhöhter Wachstumshormonspiegel bei deutlich erniedrigtem Somatomedin C Spiegel, auch bekannt als Insulin-ähnlicher Wachstumsfaktor 1 (IGF1). Der Spiegel des Wachstumshormon bindenden Proteins ist dagegen variabel ind Abhängigkeit von der Mutation. Nicht unerwähnt bleiben sollte eine Hypercholesterinämie, die mit Mutationen des Gens in Zusammenhang gebracht werden kann.

Gliederung

Wachstumshormon-Unempfindlichkeit
Insulinähnlicher Wachtumsfaktor 1 Mangel
Insulinähnlicher Wachtumsfaktor 1 Resistenz
Insulinähnlicher Wachtumsfaktor 1-Transportproteinmangel
Laron-Syndrom
GHR
SH2B1
Wachstumshormoninsensitivität mit Immundefizit

Referenzen:

1.

Goddard AD et al. (1995) Mutations of the growth hormone receptor in children with idiopathic short stature. The Growth Hormone Insensitivity Study Group.

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2.

Rosenbloom AL et al. (1990) The little women of Loja--growth hormone-receptor deficiency in an inbred population of southern Ecuador.

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3.

Arden KC et al. (1990) The receptors for prolactin and growth hormone are localized in the same region of human chromosome 5.

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4.

Barton DE et al. (1989) Chromosome mapping of the growth hormone receptor gene in man and mouse.

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5.

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6.

Berg MA et al. (1993) Diverse growth hormone receptor gene mutations in Laron syndrome.

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7.

Woods KA et al. (1996) A homozygous splice site mutation affecting the intracellular domain of the growth hormone (GH) receptor resulting in Laron syndrome with elevated GH-binding protein.

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8.

Ayling RM et al. (1997) A dominant-negative mutation of the growth hormone receptor causes familial short stature.

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9.

Laron Z et al. () Genetic pituitary dwarfism with high serum concentation of growth hormone--a new inborn error of metabolism?

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10.

Behncken SN et al. (1997) Aspartate 171 is the major primate-specific determinant of human growth hormone. Engineering porcine growth hormone to activate the human receptor.

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11.

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12.

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13.

Mauras N et al. (2000) Recombinant human insulin-like growth factor I has significant anabolic effects in adults with growth hormone receptor deficiency: studies on protein, glucose, and lipid metabolism.

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14.

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15.

Kastrup KW et al. (1975) Increased immunoreactive plasma and urinary growth hormone in growth retardation with defective generation of somatomedin a (Laron's Syndrome).

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16.

Laron Z et al. (1992) Effects of insulin-like growth factor on linear growth, head circumference, and body fat in patients with Laron-type dwarfism.

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17.

Benbassat CA et al. (2003) Are adult patients with Laron syndrome osteopenic? A comparison between dual-energy X-ray absorptiometry and volumetric bone densities.

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18.

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19.

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20.

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21.

Eicher EM et al. (1991) Growth hormone receptor (Ghr) and hemoglobin alpha-chain pseudogene 3 (Hba-ps3) map proximal to the myelocytomatosis oncogene (Myc) on mouse chromosome 15.

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22.

Walker JL et al. (1991) Effects of the infusion of insulin-like growth factor I in a child with growth hormone insensitivity syndrome (Laron dwarfism).

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23.

Aguirre A et al. (1990) High-affinity serum growth-hormone-binding protein, absent in Laron-type dwarfism, is diminished in heterozygous parents.

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24.

Guevara-Aguirre J et al. (2011) Growth hormone receptor deficiency is associated with a major reduction in pro-aging signaling, cancer, and diabetes in humans.

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25.

Pintor C et al. (1990) Correction and withdrawal of conclusion--a child with phenotypic Laron dwarfism and normal somatomedin levels.

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26.

Laron Z et al. (1989) A child with phenotypic Laron dwarfism and normal somatomedin levels.

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27.

Laron Z et al. (1988) Effect of acute administration of insulin-like growth factor I in patients with Laron-type dwarfism.

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28.

Pintor C et al. (1989) A child with phenotypic Laron dwarfism and normal somatomedin levels.

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29.

Geffner ME et al. (1987) Tissues of the Laron dwarf are sensitive to insulin-like growth factor I but not to growth hormone.

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30.

Keret R et al. (1988) Growth hormone (hGH) secretion and turnover in three patients with Laron-type dwarfism.

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31.

Daughaday WH et al. (1987) Absence of serum growth hormone binding protein in patients with growth hormone receptor deficiency (Laron dwarfism).

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32.

Merimee TJ et al. (1968) An unusual variety of endocrine dwarfism: subresponsiveness to growth hormone in a sexually mature dwarf.

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33.

Laron Z et al. (1974) Syndrome of familial dwarfism and high plasma immunoreactive growth hormone.

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34.

Daughaday WH et al. (1969) Defective sulfation factor generation: a possible etiological link in dwarfism.

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35.

Najjar SS et al. (1971) Dwarfism with elevated levels of plasma growth hormone.

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36.

Pertzelan A et al. () Genetic aspects of pituitary dwarfism due to absence or biological inactivity of growth hormone.

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37.

Golde DW et al. (1980) Peripheral unresponsiveness to human growth hormone in Laron dwarfism.

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38.

Phillips LS et al. (1980) Somatomedins (first of two parts).

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39.

Eshet R et al. (1984) Defect of human growth hormone receptors in the liver of two patients with Laron-type dwarfism.

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40.

Pierson M et al. (1978) [Laron type familial dwarfism; genetic primary somatomedin deficiency].

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41.

Saldanha PH et al. (1981) Familial dwarfism with high IR-GH: report of two affected sibs with genetic and epidemiologic considerations.

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42.

Laron Z et al. (1980) Puberty in Laron type dwarfism.

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43.

Schaefer GB et al. (1994) Facial morphometry of Ecuadorian patients with growth hormone receptor deficiency/Laron syndrome.

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44.

Souza SC et al. (1995) A single arginine residue determines species specificity of the human growth hormone receptor.

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45.

Hopwood NJ et al. (1993) Growth response of children with non-growth-hormone deficiency and marked short stature during three years of growth hormone therapy.

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46.

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47.

Baumbach L et al. (1997) Clinical, biochemical, and molecular investigations of a genetic isolate of growth hormone insensitivity (Laron's syndrome).

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48.

Guevara-Aguirre J et al. (1997) Two-year treatment of growth hormone (GH) receptor deficiency with recombinant insulin-like growth factor I in 22 children: comparison of two dosage levels and to GH-treated GH deficiency.

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49.

Woods KA et al. (1997) Phenotype: genotype relationships in growth hormone insensitivity syndrome.

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50.

Zhou Y et al. (1997) A mammalian model for Laron syndrome produced by targeted disruption of the mouse growth hormone receptor/binding protein gene (the Laron mouse).

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