Norman–Roberts syndrome

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{{Distinguish|Roberts syndrome}}

{{Infobox medical condition (new)

| synonyms = Microlissencephaly type A, Lissencephaly 2

| name = Norman–Roberts syndrome

| image = Autosomal recessive - en.svg

| image_size = 140px

| caption = This condition is inherited in an autosomal recessive manner.

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| field = neurology

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Norman–Roberts syndrome is a rare form of microlissencephaly caused by a mutation in the RELN gene.{{cite journal |vauthors=Hong SE, Shugart YY, Huang DT, Shahwan SA, Grant PE, Hourihane JO, Martin ND, Walsh CA |s2cid=67748801 |title=Autosomal recessive lissencephaly with cerebellar hypoplasia is associated with human RELN mutations |journal=Nature Genetics |volume=26 |issue=1 |pages=93–96 |year=2000 |pmid=10973257 |doi=10.1038/79246}} A small number of cases have been described. The syndrome was first reported by Margaret Grace Norman and M. Roberts et al. in 1976.{{cite journal |vauthors=Norman MG, Roberts M, Sirois J, Tremblay LJ |title=Lissencephaly |journal=Canadian Journal of Neurological Sciences |volume=3 |issue=1 |pages=39–46 |year=1976 |pmid=175907 |doi=10.1017/S0317167100025981|doi-access=free }}

Lack of reelin prevents normal layering of the cerebral cortex and disrupts cognitive development. Patients have cerebellar hypoplasia, congenital lymphedema, and hypotonia. The disorder is also associated with myopia, nystagmus and generalized seizures.{{citation needed|date=June 2020}}

Norman–Roberts syndrome is one of two known disorders caused by a disruption of the reelin-signaling pathway. The other is VLDLR-associated cerebellar hypoplasia, which is caused by a mutation in the gene coding for one of the reelin receptors, VLDLR.{{citation needed|date=November 2020}}

Disruption of the RELN gene in human patients is analogous to the malfunctioning RELN gene in the reeler mouse.{{citation needed|date=November 2020}}