Homozygous or compound heterozygous mutations of NPHP1 cause nephronophthisis 1, Senior-Loken syndrome 1, or Joubert syndrome 4.
The NPHP1 gene, which is located on chromosome 2 (2q13) spans about 85kb. Two spice variants exists with 20 and 4 exons. In the shorter splice variant, exon 4 is 376 bases longer.
Nearly 80% of patients with nephronophthisis 1 show a homozygous deletion of about 290 kb. But splice and missense mutations have also been reported.[Error: Macro 'ref' doesn't exist]
As in many patients a homozygous deletion of a large part of the gene is the cause of disease, in most cases the diagnosis can be proved by demonstrating amplification failure during the first step of sequencing analysis.
Clinic | Method | Carrier testing |
Turnaround | 5 days | |
Specimen type | genomic DNA |
Clinic | Method | Massive parallel sequencing |
Turnaround | 25 days | |
Specimen type | genomic DNA |
Clinic | Method | Genomic sequencing of the entire coding region |
Turnaround | 30 days | |
Specimen type | genomic DNA |
Clinic | Method | Multiplex Ligation-Dependent Probe Amplification |
Turnaround | 25 days | |
Specimen type | genomic DNA |
1. |
Saunier S et al. (2000) Characterization of the NPHP1 locus: mutational mechanism involved in deletions in familial juvenile nephronophthisis. |
2. |
Hildebrandt F et al. (1997) A novel gene encoding an SH3 domain protein is mutated in nephronophthisis type 1. |
3. |
NCBI article NCBI 4867 |
4. |
OMIM.ORG article Omim 607100 |
5. |
Orphanet article Orphanet ID 123874 |
6. |
Wikipedia article Wikipedia EN (NPHP1) |