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Prevalence
So far, only 3 unrelated probands with an heterozygous end-truncating mutation in LAMB1 have been reported in the medical literature. Nevertheless, more individuals will likely be found now that the MRI/clinical picture and the causative mutations are reported.

Main clinical features and inheritance
Heterozygous pathogenic variants in the LAMB1 gene cause episodic memory dysfunction of the hippocampal type starting during the sixth decade and a diffuse leukoencephalopathy inherited in an autosomal dominant manner.

Diagnosis
LAMB1 variants can be identified using molecular genetic testing, either by Sanger sequencing of the LAMB1 gene or exome/genome sequencing.