Less serious examples are benign rolandic epilepsy (2.8 per 100,000), childhood absence epilepsy (0.8 per 100,000) and juvenile myoclonic epilepsy (0.7 per 100,000). Severe syndromes with diffuse brain dysfunction caused, at least partly, by some aspect of epilepsy, are also referred to as developmental and epileptic encephalopathies. These are associated with frequent seizures that are resistant to treatment and cognitive dysfunction, for instance Lennox–Gastaut syndrome (1-2% of all persons with epilepsy), Dravet syndrome(1: 15000-40000 worldwide), and West syndrome(1-9: 100000). Genetics is believed to play an important role in epilepsies by a number of mechanisms. Simple and complex modes of inheritance have been identified for some of them. However, extensive screening have failed to identify many single gene variants of large effect. More recent exome and genome sequencing studies have begun to reveal a number of de novo gene mutations that are responsible for some epileptic encephalopathies, including CHD2 and SYNGAP1 and DNM1, GABBR2, FASN and RYR3.Syndromes in which causes are not clearly identified are difficult to match with categories of the current classification of epilepsy. Categorization for these cases was made somewhat arbitrarily. The idiopathic (unknown cause) category of the 2011 classification includes syndromes in which the general clinical features and/or age specificity strongly point to a presumed genetic cause. Some childhood epilepsy syndromes are included in the unknown cause category in which the cause is presumed genetic, for instance benign rolandic epilepsy. Others are included in symptomatic despite a presumed genetic cause (in at least in some cases), for instance Lennox-Gastaut syndrome.
Ischemic hepatitis, also known as  shock liver, is a condition defined as an acute liver injury caused by insufficient blood flow (and consequently insufficient oxygen delivery) to the liver. The decreased blood flow (perfusion) to the liver is usually due to shock or low blood pressure. However, local causes involving the hepatic artery that supplies oxygen to the liver, such as a blood clot in the hepatic artery, can also cause ischemic hepatitis. Signs and symptoms
People who develop ischemic hepatitis may have weakness, fatigue, mental confusion, and low urine production (oliguria). A small percentage of affected people may develop hepatic coma. Yellow discoloration of the skin (jaundice) can occur, but is rare and temporary, as is actual loss of function of the liver. Cause
Ischemic hepatitis can be caused by a number of reasons (that lead to low blood pressure) including:
Abnormal heart rhythm
Heart failure
Infection
Hypovolemic shock (e.g., due to profuse bleeding)
Blood clots (hepatic artery after surgery)

Mechanism
The mechanism of ischemic hepatitis depends on the etiopathogenetic origin, be it a cardiomyopathy, cardiac tamponade, trauma, or bleeding. Usually ischemic hepatitis reveals itself after a hypotensive event with increased levels of aminotransferases. Because of this, hypotension is thought to be one of the primary insults leading to ischemic hepatitis. Diagnosis
Blood testing usually shows high levels of the liver transaminase enzymes, AST and ALT, which may exceed 10,000 U/L.