Concentrations of amyloid precursor protein (APP), soluble APPα (sAPPα), soluble APPβ, neural cell adhesion molecule-1 (NCAM-1), L1 cell adhesion molecule (L1CAM), tau, phosphorylated tau, and total protein (TP) were measured in lumbar CSF from neonates in 6 groups: (1) no known neurological disease (n = 33); (2) IVH grades I to II (n = 13); (3) IVH grades III to IV (n = 12); (4) PHH (n = 12); (5) ventricular enlargement without hydrocephalus (n = 10); and (6) hypoxic ischemic encephalopathy (n = 13).
Mutations in the L1 Cell Adhesion Molecule (L1CAM) gene (MIM#308840) cause a variety of X-linked recessive neurological disorders collectively called L1 syndrome.
Mutations in the L1CAM gene cause a highly variable neurological disease described as X-linked hydrocephalus, MASA syndrome or spastic paraplegia type I.
This suggests the presence of a genetic factor on Xq27-28, different from L1CAM, which can lead to severe XLMR and a progressive neurological disorder.