In this case, it is also referred to as cryptogenic, in which genetic and sometimes hereditary influences play a role. There are known cases in which West syndrome appears in successive generations in boys; this has to do with X-chromosomal heredity. Genetic
Mutations in several genes have been associated with West syndrome. These include the Aristaless related homeobox (ARX) and  cyclin dependent kinase like 5 (CDKL5) genes. The ARX gene in particular seems to be responsible for at least some of the X linked cases. Variants in the KCNT1 gene can also in rare cases result in West syndrome. Idiopathic
Occasionally the syndrome is referred to as idiopathic West syndrome, when a cause cannot be determined. Important diagnostic criteria are:
Regular development until the onset of the attacks or before the beginning of the therapy
no pathological findings in neurological or neuroradiological studies
no evidence of a trigger for the spasmsThose are becoming rare due to modern medicine. Diagnosis
Diagnosis can be made by EEG. In case of epileptic spasms, EEG shows typical hypsarrhythmia patterns. Treatment
As of 2017, data on optimal treatment was limited. Therapies with hormones is the standard of care, namely adrenocorticotrophic hormone (ACTH), or oral
corticosteroids such as prednisone. Vigabatrin is also a common consideration, though there is a risk of visual field loss with long term use.
Cytomegalovirus)
hypoglycemia
brain damage due to asphyxiation or hypoxia (lack of oxygen, e.g. during birth), periventricular leukomalacia, cephalhematoma, cerebrovascular accident or brain damage of various types as well as that caused by premature birth. Down syndrome
West syndrome appears in 1% to 5% of infants with Down syndrome. This form of epilepsy is relatively difficult to treat in children who do not have the chromosomal abnormalities involved in Down syndrome. However, in children with Down syndrome, the syndrome is often far more mild, and the children often react better to medication. The German Down Syndrome Info Center noted in 2003 that what was normally a serious epilepsy was in such cases often a relatively benign one.EEG records for children with Down syndrome are often more symmetrical with fewer unusual findings. Although not all children can become entirely free from attacks with medication, children with Down syndrome are less likely to go on to develop Lennox-Gastaut syndrome or other forms of epilepsy than those without additional hereditary material on the 21st chromosome. The reason why it is easier to treat children with Down syndrome is not known.If, however, a child with Down syndrome has seizures that are difficult to control, the child should be assessed for autistic spectrum disorder. Cryptogenic
When a direct cause cannot be determined but the child has other neurological disorder, the case is referred to as cryptogenic West syndrome. The cryptogenic group is often considered idiopathic while referred to as "cryptogenic".Sometimes multiple children within the same family develop West syndrome.