case_images: PMC10556654_01
case_images: A timeline of events.
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case_images: PMC10556654_01_fneur-14-1255128-g001.jpg
case_images: fig1
case_images: Figure 1 provides a timeline of the events.
case_images: Skin lesion, urine organic acid analysis, serum amino acid and acylcarnitine analysis, and genetic testing results. (A) Superficial, erosive desquamating dermatitis on the buttocks of the present patient. (B) Urine organic acid analysis revealed an evident increase in methylmalonic acid levels (24.8 mumol/L; normal range: <4.0 mumol/L). (C) Serum amino acid and acylcarnitine analysis exhibited an increased propionyl carnitine/acetylcarnitine ratio (0.33; normal range: 0.02-0.2). (D) Next-generation sequencing identified a homozygous variant (c.482 G > A) in MMACHC, which was further validated by sanger sequencing.
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case_images: PMC10556654_01_fneur-14-1255128-g002.jpg
case_images: fig2
case_images: Seborrheic dermatitis was observed on his face and trunk, and the buttocks had prominent brown hyperpigmentation with desquamating dermatitis (Figure 2A). U/L; aspartate aminotransferase: 84.1 U/L), and significantly increased serum homocysteine levels (258.4 mumol/L, normal range, 5-15.0 mumol/L). Urine organic acid analysis and serum amino acid and acylcarnitine analysis showed substantially elevated urine methylmalonic acid levels (24.8 mumol/L, normal range, <4.0 mumol/L) and serum propionyl carnitine/acetylcarnitine ratio (0.33, normal range, 0.02-0.2) (Figures 2B,C). The diagnosis of late-onset cblC deficiency was further supported by whole-exome genetic sequencing, revealing a homozygous variant (c.482 G > A) in MMACHC (Figure 2D).
case_images: Serial MRI changes at three different time points. (A-C) The first MRI obtained 2 months after symptom onset (no treatment), indicating modest cerebral atrophy. (D-F) The second MRI obtained 2 years after symptom onset (no treatment), revealing bilateral hyperintensity in the cerebellum on the T2-weighted image and diffusion-weighted imaging (DWI), with hypointensity on the T1-weighted image. (G-I) The third MRI obtained 2 weeks after treatment initiation indicating minimal changes.
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case_images: PMC10556654_01_fneur-14-1255128-g003.jpg
case_images: fig3
case_images: The first MRI, obtained 2 months after symptom onset, revealed diffuse cerebral atrophy (Figures 3A-C). Subsequent MRI performed at this visit (2 years after symptom onset) revealed bilateral symmetrical lesions in the cerebellum, characterized by hyperintensity on T2-weighted images, restricted diffusion on diffusion-weighted imaging (DWI), and no enhancement (Figures 3D-F). At discharge, the patient did not experience significant clinical improvement, as well as observed changes on brain MRI (Figures 3G-I).