MedGen

CLCN2-related leukoencephalopathy is characterized by nonspecific neurologic findings, mild visual impairment from chorioretinopathy or optic atrophy, male infertility, and characteristic findings on brain MRI. Neurologic findings include mild ataxia (action tremor and gait instability following initially normal motor development; occasionally, mild spasticity), cognitive impairment in some (typically mild, rarely severe), psychiatric symptoms in some (depression and schizophrenia-like symptoms), headaches in some (usually intermittent, severe, and diffuse) and auditory symptoms in some (hearing loss, tinnitus, vertigo). Affected individuals remain ambulatory, do not require support for walking, and rarely become blind. To date CLCN2-related leukoencephalopathy has been reported or identified in 31 individuals from 30 families. It is not yet known if the findings occurring in a few individuals (i.e., epilepsy and paroxysmal kinesigenic dyskinesia) are part of the phenotypic spectrum or unrelated findings. [from GeneReviews]

Both juvenile myoclonic epilepsy and juvenile absence epilepsy are subtypes of idiopathic generalized epilepsy (EIG). For a general phenotypic description and a discussion of genetic heterogeneity of these disorders, see EIG1 (600669), EJM1 (254770), and EJA1 (607631). [from OMIM]

Familial hyperaldosteronism type II (HALD2) is an autosomal dominant disorder characterized by hypertension due to increased aldosterone, often with hypokalemia. Patients usually present before age 20 years, although some may present in infancy. The disorder shows incomplete penetrance and variable expressivity; some patients may have normal blood pressure but have an increased aldosterone:renin ratio (ARR) on laboratory testing. Spironolactone is an effective treatment (summary by Scholl et al., 2018). For a general phenotypic description and a discussion of genetic heterogeneity of familial hyperaldosteronism, see HALD1 (103900). [from OMIM]