COL4A1 VARIANT ANALYSIS IN HEREDITARY ANGIOPATHY WITH NEPHROPATHY, ANEURYSMS AND MUSCLE CRAMPS (HANAC) SYNDROME
HANAC syndrome is characterised by renal manifestations, muscle cramps that typically begin in early childhood and leukoencephalopathy with no evidence of porencephaly. Bilateral retinal arteriolar tortuosity is observed in all individuals with HANAC syndrome. Raynaud phenomenon and supraventricular arrhythmia are variably reported.
All variants known to cause HANAC syndrome are localized within the CB3[IV] fragment of COL4A1 (exons 24 and 25), which encompasses major integrin-binding sites (Plaisier et al, 2010, Am J Med Genet Part A 152A:2550-2555).
COL4A1 disease-causing variants have also been identified in patients with Porencephaly and Brain Small-Vessel Disease with Hemorrhage.
Please note: for NHS patients in England this test has been superseded with gene panel testing (please contact your local Genomic Laboratory Hub to determine the most appropriate panel). Single gene testing is only available if required urgently for clinical management.
The laboratory participates in the European Molecular Genetics Quality Network (EMQN) sequencing scheme.