CWH43 Variants Are Associated With Disease Risk and Clinical Phenotypic Measures in Patients With Normal Pressure Hydrocephalus

Philip W Tipton; Merve Atik; Alexandra I Soto-Beasley; Gregory S Day; Sanjeet S Grewal; Kaisorn Chaichana; Olga P Fermo; Colleen T Ball; Michael G Heckman; Launia J White; Zachary S Quicksall; Joseph S Reddy; Vijay K Ramanan; Prashanthi Vemuri; Benjamin D Elder; Nilufer Ertekin-Taner; Owen Ross; Neill Graff-Radford

doi:10.1212/NXG.0000000000200086

CWH43 Variants Are Associated With Disease Risk and Clinical Phenotypic Measures in Patients With Normal Pressure Hydrocephalus

Neurol Genet. 2023 Jul 19;9(5):e200086. doi: 10.1212/NXG.0000000000200086. eCollection 2023 Oct.

Authors

Philip W Tipton¹, Merve Atik¹, Alexandra I Soto-Beasley¹, Gregory S Day¹, Sanjeet S Grewal¹, Kaisorn Chaichana¹, Olga P Fermo¹, Colleen T Ball¹, Michael G Heckman¹, Launia J White¹, Zachary S Quicksall¹, Joseph S Reddy¹, Vijay K Ramanan¹, Prashanthi Vemuri¹, Benjamin D Elder¹, Nilufer Ertekin-Taner¹, Owen Ross¹, Neill Graff-Radford¹

Affiliation

¹ From the Department of Neurology (P.W.T., G.S.D., O.P.F., N.E.-T., N.G.-R.), Department of Neuroscience (M.A., A.I.S.-B., Z.S.Q., J.S.R., N.E.-T., O.R.), Department of Neurosurgery (S.S.G., K.C.), Division of Clinical Trials and Biostatistics (C.T.B., M.G.H., L.J.W.), Mayo Clinic, Jacksonville, FL; Department of Neurology (V.K.R.), Department of Radiology (P.V.), and Department of Neurosurgery (B.D.E.), Mayo Clinic, Rochester, MN.

Abstract

Background and objectives: Variants in the CWH43 gene have been associated with normal pressure hydrocephalus (NPH). We aimed to replicate these findings, identify additional CWH43 variants, and further define the clinical phenotype associated with CWH43 variants.

Methods: We determined the prevalence of CWH43 variants by whole-genome sequencing (WGS) in 94 patients with NPH. The odds of having CWH43 variant carriers develop NPH were determined through comparison with 532 Mayo Clinic Biobank volunteers without a history of NPH. For patients with NPH, we documented the head circumference, prevalence of disproportionate enlargement of subarachnoid hydrocephalus (DESH), microvascular changes on MRI quantified by the Fazekas scale, and ambulatory response to ventriculoperitoneal shunting.

Results: We identified rare (MAF <0.05) coding CWH43 variants in 15 patients with NPH. Ten patients (Leu533Terfs, n = 8; Lys696Asnfs, n = 2) harbored previously reported predicted loss-of-function variants, and combined burden analysis confirmed risk association with NPH (OR 2.60, 95% CI 1.12-6.03, p = 0.027). Additional missense variations observed included Ile292Thr (n = 2), Ala469Ser (n = 2), and Ala626Val (n = 1). Though not quite statistically significant, in single variable analysis, the odds of having a head circumference above the 75th percentile of normal controls was more than 5 times higher for CWH43 variant carriers compared with that for noncarriers (unadjusted OR 5.67, 95% CI 0.96-108.55, p = 0.057), and this was consistent after adjusting for sex and height (OR 5.42, 95% CI 0.87-106.37, p = 0.073). DESH was present in 56.7% of noncarriers and only 21.4% of carriers (p = 0.016), while sulcal trapping was also more prevalent among noncarriers (67.2% vs 35.7%, p = 0.030). All 8 of the 15 variant carriers who underwent ventriculoperitoneal shunting at our institution experienced ambulatory improvements.

Discussion: CWH43 variants are frequent in patients with NPH. Predicted loss-of-function mutations were the most common; we identified missense mutations that require further study. Our findings suggest that congenital factors, rather than malabsorption or vascular dysfunction, are primary contributors to the CWH43-related NPH clinical syndrome.