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Morales et al. J Transl Genet Genom 2022;6:257-65 Journal of Translational
DOI: 10.20517/jtgg.2022.01
Genetics and Genomics

Case Report Open Access

Clinical characterization of a new individual with
mild SC4MOL deficiency: diagnostic and therapeutic

implications

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1
2
1
J. Andres Morales , Cynthia J. Curry , Christina G. Tise , Lisa Kratz , Gregory M. Enns 1
1
Division of Medical Genetics, Pediatrics, Stanford University, Stanford, CA 94305, USA.
2
Genetic Medicine, Pediatrics, UCSF Fresno, Fresno, CA 93701, USA.
3
Biochemical Genetics Laboratory, Kennedy Krieger Institute, Baltimore, MD 21205, USA.
Correspondence to: J. Andres Morales, MD, Division of Medical Genetics, Pediatrics, Stanford University, 453 Quarry Road,
Stanford, CA 94305, USA. E-mail: andresmc@stanford.edu.
How to cite this article: Morales JA, Curry CJ, Tise CG, Kratz L, Enns GM. Clinical characterization of a new individual with mild
SC4MOL deficiency: diagnostic and therapeutic implications. J Transl Genet Genom 2022;6:257-65.
https://dx.doi.org/10.20517/jtgg.2022.01

Received: 14 Jan 2022 First Decision: 2 Apr 2022 Revised: 19 Apr 2022 Accepted: 12 May 2022 Published: 2 Jun 2022
Academic Editors: Andrea L. Gropman, Sanjay Gupta Copy Editor: Fangling Lan Production Editor: Fangling Lan

Abstract
Sterol C4-methyloxidase-like (SC4MOL) deficiency is an autosomal recessive condition caused by biallelic
pathogenic variants in MSMO1, resulting in the accumulation of 4-monomethyl and 4,4′-dimethyl sterols due to an
enzymatic block in the cholesterol synthesis pathway. SC4MOL deficiency was first reported in 2011, with only
seven additional cases from five unrelated families described in the literature since. Based on these reports, the
most characteristic clinical features include the triad of microcephaly, congenital cataracts, and psoriatic
dermatitis, followed by delayed growth and puberty, and neurodevelopmental problems. Herein, we describe an 8-
year-old boy who presented with congenital cataracts and developmental delay at age 6 months and was found to
have biallelic variants in MSMO1 by trio exome sequencing. Initial total methylsterol levels were elevated but
responsive to statin therapy, while total cholesterol levels remained normal throughout. Available clinical and
biochemical data suggest this individual could represent the mildest case of SC4MOL deficiency to date.

Keywords: SC4MOL deficiency, microcephaly, cataract, psoriasiform dermatitis, MSMO1

© The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0
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