Nail-patella syndrome

出自KMU Wiki

• AD inheritance
• Genetic defect
  • Haploinsufficiency for the LIM homeodomain transcription factor ~LMX1B (chromosome 9q34)
  • ~LMX1B regulates a3(IV), a4(IV) and type III collagen, podocin, and CD2AP in the slit-pore membranes connecting podocytes
  • Haploinsufficiency
    • Wikipedia
      • Haploinsufficiency occurs when a diploid organism only has a single functional copy of a gene (with the other copy inactivated by mutation) and the single functional copy of the gene does not produce enough of a gene product (typically a protein) to bring about a wild-type condition, leading to an abnormal or diseased state. It is responsible for some but not all autosomal dominant disorders.
    • Harrison's
      • Often occurrs in mutations of transcription factors or rate-limiting enzymes
• Iliac horns on pelvis, dysplasia of dorsal limbs (patella, elbows, and nails), neural-sensory hearing impairment, glaucoma
• GN (30%)
  • More common in females for unknown reasons
  • At 30 y/o: hematuria, proteinuria, renal failure
  • Renal transplantation is indicated
• Pathology
  • Electron microscope
    • "Moth-eaten" GBM (lucent damage to the lamina densa of the GBM)