biostudies-literatureUnknownCesur Baltacı HN<h4>Introduction</h4>Cerebrotendinous xanthomatosis (CTX) is a rare, autosomal recessive lipid storage disorder characterized by the accumulation of cholesterol and cholestanol in various tissues. It is caused by pathogenic variants in the <i>CYP27A1</i> gene, which encodes the mitochondrial enzyme sterol 27-hydroxylase.<h4>Case presentation</h4>Here, we present an 8-year-old boy with attention-deficit/hyperactivity disorder, born to non-consanguineous parents. He was referred to our center for <i>CYP27A1</i> gene analysis and genetic counseling, following the identification of a homozygous deletion in exon 6 of the <i>CYP27A1</i> gene in his mother. His plasma cholestanol levels were also elevated, supporting a diagnosis of CTX. The proband's father had a history of epilepsy and mild intellectual disability. Genetic analysis of the father revealed a novel heterozygous p.(Glu170Valfs*16) variant in the <i>CYP27A1</i> gene. Based on these findings, the proband was found to carry a compound heterozygous variant in <i>CYP27A1</i>, confirming the molecular diagnosis of CTX. After genetic counseling, treatment with chenodeoxycholic acid (CDCA) was initiated. Plasma cholestanol levels normalized, and some clinical symptoms showed improvement after 2 months of treatment.<h4>Conclusions</h4>Early genetic screening of presymptomatic family members is critical, as timely initiation of CDCA therapy can prevent or significantly attenuate the clinical progression of CTX.Molecular syndromologyhttps://www.ebi.ac.uk/biostudies/studies/S-EPMC12503532biostudies-literatureA Novel Compound Heterozygous &lt;i&gt;CYP27A1&lt;/i&gt; Variant in Cerebrotendinous Xanthomatosis: A Case Report from a Non-Consanguineous Family.PMC12503532Teber STCesur Baltacı HNYurur Kutlay NTukun ACoskun TSaglam Ada BfalseA Novel Compound Heterozygous &lt;i&gt;CYP27A1&lt;/i&gt; Variant in Cerebrotendinous Xanthomatosis: A Case Report from a Non-Consanguineous Family.<h4>Introduction</h4>Cerebrotendinous xanthomatosis (CTX) is a rare, autosomal recessive lipid storage disorder characterized by the accumulation of cholesterol and cholestanol in various tissues. It is caused by pathogenic variants in the <i>CYP27A1</i> gene, which encodes the mitochondrial enzyme sterol 27-hydroxylase.<h4>Case presentation</h4>Here, we present an 8-year-old boy with attention-deficit/hyperactivity disorder, born to non-consanguineous parents. He was referred to our center for <i>CYP27A1</i> gene analysis and genetic counseling, following the identification of a homozygous deletion in exon 6 of the <i>CYP27A1</i> gene in his mother. His plasma cholestanol levels were also elevated, supporting a diagnosis of CTX. The proband's father had a history of epilepsy and mild intellectual disability. Genetic analysis of the father revealed a novel heterozygous p.(Glu170Valfs*16) variant in the <i>CYP27A1</i> gene. Based on these findings, the proband was found to carry a compound heterozygous variant in <i>CYP27A1</i>, confirming the molecular diagnosis of CTX. After genetic counseling, treatment with chenodeoxycholic acid (CDCA) was initiated. Plasma cholestanol levels normalized, and some clinical symptoms showed improvement after 2 months of treatment.<h4>Conclusions</h4>Early genetic screening of presymptomatic family members is critical, as timely initiation of CDCA therapy can prevent or significantly attenuate the clinical progression of CTX.2025-01-01T00:00:00Z2025 Jun2026-06-04T07:53:11.124Z2026-05-07T03:08:27.712ZS-EPMC125035324106405010.1159/000547016