Hereditary cystatin C amyloid angiopathy explained

Hereditary cystatin C amyloid angiopathy
Synonyms:Hereditary cerebral hemorrhage with amyloidosis

Hereditary cystatin C amyloid angiopathy (HCCAA) is a rare, fatal type of hereditary cerebral amyloid angiopathy found almost exclusively in Iceland. A mutation in the protein cystatin C leads to amyloid (protein aggregate) dispositions in arteries in the brain, resulting in repeated brain hemorrhages.[1] [2]

The condition is inherited in an autosomal dominant fashion. All known cases have occurred in Iceland — most can be traced to Breiðafjörður in the northwest of Iceland[3]  — with the exception of one patient in the US with a sporadic mutation.[4]

Symptoms are related to brain hemorrhage and include dementia and paralysis. They typically appear in the late teens or early twenties, with the average age of death being around 30. As of 2019, around 20 to 30 carriers are thought to be alive.[5]

Signs and symptoms

The most typical initial symptoms are massive sensorimotor hemiparesis, with or without aphasia or neglect symptoms. Exercise appears to be the initial cause of the symptoms, although this is not always the case. While the majority of patients have typical symptoms when they first arrive, atypical presentations, such as those involving primary mental symptoms like progressive dementia or psychiatric symptoms, are uncommon. The few patients who present in their fifth decade or later are more likely to have this atypical presentation, though these cases have been extremely uncommon.[6]

Notes and References

  1. Levy E, Lopez-Otin C, Ghiso J, Geltner D, Frangione B . May 1989 . Stroke in Icelandic patients with hereditary amyloid angiopathy is related to a mutation in the cystatin C gene, an inhibitor of cysteine proteases . J. Exp. Med. . 169 . 5 . 1771–8 . 10.1084/jem.169.5.1771 . 2189307 . 2541223.
  2. Levy . E . Jaskolski . M . Grubb . A . January 2006 . The role of cystatin C in cerebral amyloid angiopathy and stroke: cell biology and animal models . Brain Pathol. . 16 . 1 . 60–70 . 10.1111/j.1750-3639.2006.tb00562.x . 8095742 . 16612983.
  3. 16612982 . 16 . 1 . Hereditary cystatin C amyloid angiopathy: genetic, clinical, and pathological aspects. . Jan 2006 . Brain Pathol . 55–9 . 10.1111/j.1750-3639.2006.tb00561.x. A . Palsdottir . Ao . Snorradottir . L . Thorsteinsson . 8095917 .
  4. Web site: Hvað getið þið sagt mér um arfgeng heilablóðföll? . 2023-10-30 . Vísindavefurinn . is.
  5. Web site: Arfgeng heilablæðing í fimm fjölskyldum — RÚV.is . 2023-10-30 . RÚV.
  6. Sveinbjörnsdóttir . Sigurlaug . Blöndal . Hannes . Gudmundsson . Gretar . Kjartansson . Ólafur . Jónsdóttir . Sif . Gudmundsson . Gunnar . Progressive dementia and leucoencephalopathy as the initial presentation of late onset hereditary cystatin-C amyloidosis Clinicopathological presentation of two cases . Journal of the Neurological Sciences . Elsevier BV . 140 . 1–2 . 1996 . 0022-510X . 10.1016/0022-510x(96)00094-9 . 101–108. 8866434 .