Cerebrotendinous xanthomatosis; a genetic condition: Clinical profile of three patients from a rural Indian family and review of literature

Malar rash and hand tremor in early symptoms of cerebrotendinous xanthomatosis and the effect of chenodeoxycholic acid on them

BACKGROUND

Cerebrotendinous xanthomatosis (CTX, OMIM #213700) is a rare but treatable lipid storage disease resulting from mutations in the CYP27A1 gene.

PURPOSE

The study aims to evaluate patients diagnosed with CTX and reveal new information, especially about the signs of CTX and patients' response to the treatment.

METHODS

The study was conducted retrospectively in 12 definitively diagnosed CTX patients. The patients' clinical, laboratory, imaging, genetic findings, and chenodeoxycholic acid (CDCA) treatment results were analyzed.

RESULTS

The median age at diagnosis for the patients was 16.5 years (minimum-maximum: 7-32). Juvenile cataracts, detected in more than 90% (11/12) of the patients, were the most common clinical finding. Malar rash, not previously reported in the literature for CTX, was present in 75% (9/12) of the patients. Hand tremors, the first neurological symptom, occurred in adolescence and were the initial symptom of the disease in five patients. Hand tremors were present in 83.3% (10/12) of the patients. Hand tremors (in 5 patients) and malar rash (in 2 patients) were clinical findings with full recovery due to the CDCA treatment.

CONCLUSION

The study defines the malar rash finding, which has not been reported in the literature before, as a possible new clinical finding in CTX disease, attributed to its partial or full recovery with CDCA treatment. Additionally, as a novelty in the literature, our study highlights the full recovery of neurological findings, such as hand tremors, in CTX. Patients presenting with hand tremors and malar rash, especially in adolescence, should undergo CTX investigation for early diagnosis and treatment.

First case series of Polish patients with cerebrotendinous xanthomatosis and systematic review of cases from the 21st century

Cerebrotendinous xanthomatosis (CTX) is an inborn error of metabolism caused by recessive variants in the cytochrome P450 CYP27A1 gene. CTX is said to manifest with childhood-onset chronic diarrhea and the classic triad of juvenile-onset cataracts, Achilles tendons xanthomas, and progressive ataxia. It is currently one of the few inherited neurometabolic disorders amenable to a specific treatment. The diagnosis may be significantly delayed resulting in permanent neurological impairment. A retrospective review of the clinical characteristics and diagnostic findings in case series of six Polish patients with CTX. Additional retrospective review of symptoms and pathogenic variants of 568 CTX available cases and case series from the past 20 years. To the best of our knowledge, this is the widest review of CTX cases reported in years 2000-2021. We report the largest cohort of Polish patients ever published, with the identification of two hot-spot mutations. During the review of available 568 cases, we found significant differences in the clinical phenotypes and the localization of variants within the gene between Asian and non-Asian populations. These findings may facilitate molecular testing in the Polish and Asian populations. Invariably better screening for CTX and wider awareness is needed.

Lipid metabolic pathways converge in motor neuron degenerative diseases

Motor neuron diseases (MNDs) encompass an extensive and heterogeneous group of upper and/or lower motor neuron degenerative disorders, in which the particular clinical outcomes stem from the specific neuronal component involved in each condition. While mutations in a large number of molecules associated with lipid metabolism are known to be implicated in MNDs, there remains a lack of clarity regarding the key functional pathways involved, and their inter-relationships. This review highlights evidence that defines defects within two specific lipid (cholesterol/oxysterol and phosphatidylethanolamine) biosynthetic cascades as being centrally involved in MND, particularly hereditary spastic paraplegia. We also identify how other MND-associated molecules may impact these cascades, in particular through impaired organellar interfacing, to propose ‘subcellular lipidome imbalance’ as a likely common pathomolecular theme in MND. Further exploration of this mechanism has the potential to identify new therapeutic targets and management strategies for modulation of disease progression in hereditary spastic paraplegias and other MNDs.

Clinical and genetic characteristics of Chinese patients with cerebrotendinous xanthomatosis

BACKGROUND

Cerebrotendinous xanthomatosis (CTX) is a rare inborn lipid-storage disease caused by mutations in the sterol 27-hydroxylase (CYP27A1) gene with an autosomal recessive pattern of inheritance. To date, only 19 CTX patients from 16 families have been reported in the Chinese population.

RESULTS

Three novel likely pathogenic mutations (c.368_374delCCAGTAC, c.389 T > A and c.571C > T) and 7 previously reported pathogenic mutations (c.379C > T, c.435G > T, c.1016C > T, c.1214G > A, c.1263 + 1G > A, c.1420C > T and c.1435C > T) were identified. In addition, we summarized the genotypes and phenotypes of reported Chinese CTX patients. The most predominant mutations in CYP27A1 were c.410G > A and c.379C > T, and the most common clinical manifestations were pyramidal signs, xanthomatosis, cerebellar ataxia, and cognitive impairment.

CONCLUSION

Our study broadens the genetic and clinical spectrum of CTX and provides insightful information to help better diagnose and understand the disease.

Clinical and genetic characteristics of Chinese patients with cerebrotendinous xanthomatosis

Background

Cerebrotendinous xanthomatosis (CTX) is a rare inborn lipid-storage disease caused by mutations in the sterol 27-hydroxylase (CYP27A1) gene with an autosomal recessive pattern of inheritance. To date, only 19 CTX patients from 16 families have been reported in the Chinese population.

Results

Three novel likely pathogenic mutations (c.368_374delCCAGTAC, c.389 T > A and c.571C > T) and 7 previously reported pathogenic mutations (c.379C > T, c.435G > T, c.1016C > T, c.1214G > A, c.1263 + 1G > A, c.1420C > T and c.1435C > T) were identified. In addition, we summarized the genotypes and phenotypes of reported Chinese CTX patients. The most predominant mutations in CYP27A1 were c.410G > A and c.379C > T, and the most common clinical manifestations were pyramidal signs, xanthomatosis, cerebellar ataxia, and cognitive impairment.

Conclusion

Our study broadens the genetic and clinical spectrum of CTX and provides insightful information to help better diagnose and understand the disease.