"Heterozygous HTRA1-related cerebral small vessel disease, also known as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy type 2 (CADASIL2), is a very rare monogenic cerebral small vessel disease."
"Heterozygous HTRA1-related cerebral small vessel disease is an HTRA1-related cerebral small vessel disease, and thus is closely related to, but distinct from, cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL)."
"Heterozygous HTRA1-related cerebral small vessel disease accounts for ~5% of familial cerebral small vessel disease cases, possibly making it the second-most common monogenic cerebral small vessel disease after CADASIL 6. The condition tends to clinically manifest between the third and sixth decades of life 1-3."
"The clinical presentation of heterozygous HTRA1-related cerebral small vessel disease may be asymptomatic, but when symptomatic, is similar to CARASIL, albeit generally milder 1,2."
"Heterozygous HTRA1-related cerebral small vessel disease, as its name suggests, is caused by a monoallelic mutation in HTRA1, the same gene implicated in CARASIL 1-4. The mechanisms by which a mutation in a single allele causes cerebral small vessel disease is not fully elucidated, but is thought to be due to either haploinsufficiency or dominant-negative effects 1,2. In some instances, the monoallelic mutation may demonstrate an autosomal dominant pattern of inheritance through a pedigree, however, the penetrance is low 1-3."