A congenital disorder characterized by the presence of extremely hypoplastic gonads preventing the development of secondary sex characteristics.

Neural tube defects are the second most common type of birth defect after congenital heart defects. The 2 most common NTDs are open spina bifida, also known as spina bifida cystica (SBC) or myelomeningocele, and anencephaly (see 206500) (Detrait et al., 2005). Spina bifida occulta (SBO), a bony defect of the spine covered by normal skin, is a mild form of spina bifida that is often asymptomatic. The term 'spinal dysraphia' refers to both SBC and SBO (Botto et al., 1999; Fineman et al., 1982). The most severe neural tube defect, craniorachischisis (CRN), leaves the neural tube open from the midbrain or rostral hindbrain to the base of the spine (summary by Robinson et al., 2012). Neural tube defects represent a complex trait with multifactorial etiology encompassing both genetic and environmental components (summary by Bartsch et al., 2012 and Lei et al., 2014). An X-linked form of spina bifida has been suggested; see 301410. See also folate-sensitive neural tube defects (601634), which are caused by genes involved in folate metabolism.

A form of lissencephaly characterized by an uneven cortical surface with a so called 'cobblestone' appearace. There are no distinguishable cortical layers.

Cerebellar dysplasia (abnormal growth or development) is defined by abnormal cerebellar foliation, white matter arborization, and gray-white matter junction. Cerebellar dysplasia is a neuroimaging finding that describes abnormalities of both the cerebellar cortex and white matter and is associated with variable neurodevelopmental outcome. Dysplasia may globally involve the cerebellum or affect only one cerebellar hemisphere. In addition, cerebellar dysplasia may be associated with cortical/subcortical cysts.

The presence of developmental dysplasia of the retina.