A neurological phenotype in nail patella syndrome (NPS) patients illuminated by studies of murine Lmx1b expression.
Nail patella syndrome (NPS) is an autosomal dominant disorder affecting development of the limb, kidney and eye. NPS is the result of heterozygous loss-of-function mutations in the LIM-homeodomain transcription factor, LMX1B. Recent studies suggest that the NPS phenotype may be more extensive than recognized previously including neurologic and neurobehavioral aspects. To determine whether these findings correlated with the expression of Lmx1b during development, an internal ribosomal entry site-LacZ reporter was inserted into the 3'UTR of the endogenous murine gene. The pattern of Lmx1b expression during the development of the limb, eye and kidney correlates with the NPS phenotype. Additional sites of expression were observed in the central nervous system (CNS). The effects of the absence of Lmx1b in the CNS were determined in lmx1b-/- mice by histology and immunocytochemistry. Lmx1b is required for the differentiation and migration of neurons within the dorsal spinal cord. The inability of afferent sensory neurons to migrate into the dorsal horn is entirely consistent with diminished pain responses in NPS patients.
Dunston
Jennifer A
JA
McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore MD 21205, USA.
Reimschisel
Tyler
T
Ding
Yu-Qiang
YQ
Sweeney
Elizabeth
E
Johnson
Randy L
RL
Chen
Zhou-Feng
ZF
McIntosh
Iain
I
D000818:Animals; D002490:Central Nervous System / Q000196:embryology*; D002493:Central Nervous System Diseases / Q000196:embryology / Q000235:genetics; D004195:Disease Models, Animal; D005260:Female; D018398:Homeodomain Proteins / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D007668:Kidney / Q000002:abnormalities / Q000196:embryology; D060850:LIM-Homeodomain Proteins; D017880:Limb Deformities, Congenital / Q000196:embryology / Q000235:genetics; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D009261:Nail-Patella Syndrome / Q000196:embryology / Q000235:genetics*; D009475:Neurons, Afferent / Q000502:physiology; D010641:Phenotype; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics
D018398:Homeodomain Proteins; C112149:LIM homeobox transcription factor 1 beta; D060850:LIM-Homeodomain Proteins; D014157:Transcription Factors