Neurodevelopmental disorder with or without hyperkinetic movements and seizures, autosomal dominant

An autosomal dominant neurodevelopmental disorder characterized by severe intellectual disability and developmental delay, absent speech, muscular hypotonia, dyskinesia, and hyperkinetic movements. Cortical blindness, cerebral atrophy, and seizures are present in some patients.

Developmental and epileptic encephalopathy 41

A form of epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent. DEE41 inheritance is autosomal dominant.

Microcephaly, seizures, and developmental delay

An autosomal recessive neurodevelopmental disorder characterized by infantile-onset seizures, microcephaly, severe intellectual disability and delayed motor milestones with absent speech or only achieving a few words. Most patients also have behavioral problems with hyperactivity. Microcephaly is progressive and without neuronal migration or structural abnormalities, consistent with primary microcephaly.

Neurodevelopmental disorder with seizures, hypotonia, and brain imaging abnormalities

An autosomal recessive neurodevelopmental disorder characterized by global developmental delay, hypotonia, severe to profound intellectual disability, early-onset epilepsy, and microcephaly. Neuroimaging shows cerebral atrophy, thin corpus callosum and hypomyelination in a majority of cases. Death in childhood may occur.

Episodic ataxia 1

An autosomal dominant disorder characterized by brief episodes of ataxia and dysarthria. Neurological examination during and between the attacks demonstrates spontaneous, repetitive discharges in the distal musculature (myokymia) that arise from peripheral nerve. Nystagmus is absent.

Generalized epilepsy with febrile seizures plus 1

A rare autosomal dominant, familial condition with incomplete penetrance and large intrafamilial variability. Patients display febrile seizures persisting sometimes beyond the age of 6 years and/or a variety of afebrile seizure types. This disease combines febrile seizures, generalized seizures often precipitated by fever at age 6 years or more, and partial seizures, with a variable degree of severity.

Lissencephaly, X-linked 2

A classic type lissencephaly associated with abnormal genitalia. Patients have severe congenital or postnatal microcephaly, lissencephaly, agenesis of the corpus callosum, neonatal-onset intractable epilepsy, poor temperature regulation, chronic diarrhea, and ambiguous or underdeveloped genitalia.

Developmental and epileptic encephalopathy 3

A severe form of epilepsy characterized by frequent tonic seizures or spasms beginning in infancy with a specific EEG finding of suppression-burst patterns, characterized by high-voltage bursts alternating with almost flat suppression phases. DEE3 is characterized by a very early onset, erratic and fragmentary myoclonus, massive myoclonus, partial motor seizures and late tonic spasms. The prognosis is poor, with no effective treatment, and children with the condition either die within 1 to 2 years after birth or survive in a persistent vegetative state.

Developmental and epileptic encephalopathy 64

A form of epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent. DEE64 is an autosomal dominant form characterized by onset of seizures usually in the first year of life. Seizure types are variable and include focal dyscognitive and generalized tonic-clonic seizures, as well as febrile seizures in the mildest affected individuals. Seizures tend to respond to medical treatment.

Multiple congenital anomalies-hypotonia-seizures syndrome 4

An autosomal recessive syndrome characterized by onset of refractory seizures in the first months of life. Additional clinical features include severe global developmental delay, dysmorphic facial features, and skeletal, renal and ophthalmic anomalies. At the cellular level, the disorder is caused by a defect in the synthesis of glycosylphosphatidylinositol (GPI).

Developmental and epileptic encephalopathy 30

A form of epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent.

Developmental and epileptic encephalopathy 17

A severe neurologic disorder characterized by onset of intractable seizures in the first weeks or months of life and usually associated with EEG abnormalities. Affected infants have very poor psychomotor development and may have brain abnormalities, such as cerebral atrophy or thin corpus callosum. Some patients may show involuntary movements.

Focal segmental glomerulosclerosis and neurodevelopmental syndrome

An autosomal dominant disorder characterized by global developmental delay associated with variable features of focal segmental glomerulosclerosis, a renal pathology defined by the presence of segmental sclerosis in glomeruli and resulting in proteinuria, reduced glomerular filtration rate and progressive decline in renal function. Some patients have transient proteinuria and others require renal transplant. Neurodevelopmental features are also variable, with some patients having only mildly impaired intellectual development, and others having a severe developmental disorder associated with early-onset refractory seizures or epileptic encephalopathy. Additional features, including feeding difficulties, poor overall growth, and non-specific dysmorphic facial features, are commonly observed.

Developmental and epileptic encephalopathy 69

A form of epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent. DEE69 is an autosomal dominant form characterized by refractory seizures, hypotonia, and profoundly impaired development often associated with macrocephaly, hyperkinetic movements, and contractures. The disorder can sometimes result in early death. Some patients may have a favorable seizure response to topiramate medication.

Seizures, benign familial infantile, 3

A form of benign familial infantile epilepsy, a neurologic disorder characterized by afebrile seizures occurring in clusters during the first year of life, without neurologic sequelae. BFIS3 inheritance is autosomal dominant.

Polyendocrine-polyneuropathy syndrome

A progressive endocrine and neurodevelopmental disorder manifesting early in childhood with growth retardation and recurrent episodes of profound asymptomatic hypoglycemia. PEPNS is characterized by central hypothyroidism, hypogonadotropic hypogonadism, incomplete puberty, progressive non-autoimmune insulin-dependent diabetes mellitus, peripheral demyelinating sensorimotor polyneuropathy, and cerebellar and pyramidal signs.

Developmental and epileptic encephalopathy 72

A form of epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent. DEE72 is an autosomal dominant form with variable severity and onset in infancy.

Generalized epilepsy with febrile seizures plus 12

An autosomal dominant neurologic disorder with variable expressivity and incomplete penetrance. Affected individuals have variable types of seizures, most often febrile seizures, sometimes combined with non-febrile focal or generalized seizures. Rarely, afebrile tonic-clonic seizures have been observed.

Developmental and epileptic encephalopathy 55

A form of epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent. DEE55 is an autosomal recessive condition.