1. Introduction
Cerebrotendinous xanthomatosis (CTX) is a rare inherited disorder of
lipid storage characterized by abnormal deposition of cholestanol and
cholesterol in multiple tissues, particularly in the brain and tendons1. Mutations in CYP27A1 lead to a deficiency in
sterol 27-hydroxylase 2. The deficiency of this enzyme
prevents cholesterol being converted into bile acid chenodeoxycholic
acid. The block in the synthesis of this bile acid creates the
accumulation of bile acid pathway intermediates and cholestanol in the
blood and tissues of the affected individuals. The balance between
synthesis and catabolism of cholesterol should be tightly regulated to
ensure normal cellular processes 3. Up to now, more
than 400 cases have been reported worldwide 4. The
clinical manifestations usually start at infancy and develop during the
first and second decades of life 4. Patients with CTX
demonstrate diverse manifestations with multi-organ involvement and an
extensive range of neurological and non-neurological symptoms. The
neurological features of CTX reported in the literature include
pyramidal and cerebellar signs, sensory-motor peripheral neuropathy,
intellectual disability, and dementia. Common non-neurological disorder
include early-onset bilateral cataract in childhood, formation of tendon
xanthomas (most often in the Achilles’ tendons), and diarrhea5,6. In addition, patients with CTX suffer from severe
premature atherosclerosis, pulmonary involvement, and osteoporosis with
repeated bone fractures 7. A diagnosis of CTX is made
based on clinical findings, biochemical testing, neuroimaging, and
molecular genetic analysis 8,9. This is the first
report of a CTX patient with infertility due to azoospermia.