Laboratory for Molecular Diagnostics
Center for Nephrology and Metabolic Disorders

LIM homeobox transcription factor 1 beta

The LMX1B gene encodes a transcription factor which among others regulates the transcription of the collagen 4 genes essential for the glomerular basement membrane. Mutation cause the autosomal dominat nail-patella syndrome.

Epidemiology

The incidence of the disease caused by LMX1B mutations is about 1 in 50,000 live births. The probability of new mutations seems to increase with father's age.

Phenotype

Mutations of the LMX1B gene cause an autosomal dominant disorder called nail-patella syndrome, which involves skeletal abnormalities (dysplasia of the nails, patellar aplasia or hypoplasia, iliac horns, dysplasia of the elbows) and is often associated with hereditary glaucoma and progressive nephropathy.

Gene Regulation

The gene product of LMX1B is a LIM-homeodomain transcription factor, which plays a role in skeletal and kidney development. It regulates normal patterning of the dorsoventral axis of the limbs. In the kidneys the gene is predominantly expressed by podocytes, where it regulates the translation of many crucial genes, such as COL4A4, COL4A3, CD2AP, NPHS2, and NPHS1.

Genetests:

Clinic Method Carrier testing
Turnaround 5 days
Specimen type genomic DNA
Clinic Method Multiplex Ligation-Dependent Probe Amplification
Turnaround 20 days
Specimen type genomic DNA
Clinic Method Genomic sequencing of the entire coding region
Turnaround 5 days
Specimen type genomic DNA
Clinic Method Massive parallel sequencing
Turnaround 25 days
Specimen type genomic DNA

Related Diseases:

Nail-patella syndrome
LMX1B

References:

1.

Hamlington JD et al. (2000) Deletion of a branch-point consensus sequence in the LMX1B gene causes exon skipping in a family with nail patella syndrome.

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2.

Morello R et al. (2001) Regulation of glomerular basement membrane collagen expression by LMX1B contributes to renal disease in nail patella syndrome.

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3.

Bongers EM et al. (2002) Nail-patella syndrome. Overview on clinical and molecular findings.

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4.

Dunston JA et al. (2004) The human LMX1B gene: transcription unit, promoter, and pathogenic mutations.

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5.

Marini M et al. (2005) Interaction of the LMX1B and PAX2 gene products suggests possible molecular basis of differential phenotypes in Nail-Patella syndrome.

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6.

Bongers EM et al. (2005) Genotype-phenotype studies in nail-patella syndrome show that LMX1B mutation location is involved in the risk of developing nephropathy.

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7.

Browning MC et al. (1988) Renal histopathology of the nail-patella syndrome in a two-year-old boy.

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8.

Lichter PR et al. (1997) Cosegregation of open-angle glaucoma and the nail-patella syndrome.

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9.

Dreyer SD et al. (1998) Mutations in LMX1B cause abnormal skeletal patterning and renal dysplasia in nail patella syndrome.

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10.

Vollrath D et al. (1998) Loss-of-function mutations in the LIM-homeodomain gene, LMX1B, in nail-patella syndrome.

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11.

McIntosh I et al. (1998) Mutation analysis of LMX1B gene in nail-patella syndrome patients.

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Update: Sept. 26, 2018