(PVNH  acronym for  PeriVentricular Nodular Heterotopia)

Malformation of the cerebral cortex due to an abnormality of neuronal migration, characterized by the appearance in an inadequate localization of nodules of heterotopic neurons. It can occur in a diffuse or localized form (between the subependymal area and the subcortical area of the brain) and affect one or two cerebral hemispheres.

First symptoms usually around 10 years of age by epileptic seizures. Intelligence usually not or moderately affected. The severity of the phenotype observed in patients is, according to some studies, proportional to the number and size of heterotopic nodules. The risk ofstroke  seems to be increased.

From a genetic point of view, one distinguishes:

-        PVNH1 [MIM 300 049]: mutation of the FLNA gene (Xq28) (see Filaminopathies); it mainly affects heterozygous girls.

-        PVNH2 [MIM 608 097]: mutation of the ARFGEF2 gene (20q13)

-        PVNH3 [MIM 608 098]: mutation in 5p

-        PVNH5 [MIM 612 881]: deletion in 5q

-        PVNH6 [MIM 615 544]: mutation of the ERMARD gene (6q27)

-        PVNH7 [MIM 617 201]: mutation of the NEDD4L gene (18q21)

-        PVNH8 [MIM 618 185]: mutation of the ARF1 gene (1q42)

-        PVNH9 [MIM 618 918]: mutation of the MAP1B gene (5q13)

The HPVNH4 type, formerly considered as a variant of Ehlers-Danlos disease, is now assimilated to the PVNH1 group because it is due to a mutation in the FLNA gene

Anesthetic implications: 

epilepsy

References : 

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Updated: December 2021