Parisi et al listed a strategy for making the diagnosis of Joubert Syndrome. The authors are from the University of Washington in Seattle.
Patient selection: suspected Joubert Syndrome
Parameters:
(1) molar tooth sign on brain MRI
(2) renal dysfunction
(3) Leber congenital amaurosis
Molar Tooth Sign |
Renal Function |
Leber Congenital Amaurosis |
Next Step |
absent |
NA |
NA |
consider alternative diagnosis |
present |
absent |
NA |
analyze AHI1 |
present |
present |
NA |
analyze NPHP1 |
present |
NA |
present |
analyze CEP290 |
where:
• AHI1 is at 6q23.3 (JBTS3)
• CEP290 is at 12q21.32 (JBTS5)
• NPHP1 is at 2q13 (JBTS4)
If the molar tooth sign is present and a mutation is found in one of the implicated genes, then diagnosis established.
If the molar tooth sign is present and a mutation is not found in one of the implicated genes, then consider alternative mutations:
(1) 9q34.3 (JBTS1)
(2) 11p12-11q13.3 (JBTS2, CORS2)
(3) others
Specialty: Genetics