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Clinical heterogeneity and prognosis in combined methylmalonic aciduria and homocystinuria (cblC)
Rosenblatt DS, Aspler AL, Shevell MI, Pletcher BA, Fenton WA, Seashore MR.. Journal of inherited metabolic disease, 1997-08-01
Topic: Brain proteins, microglia and lab models
The clbC form of methylmalonic acidaemia is a rare and poorly understood condition which results from impaired biosynthesis of methylcobalamin and adenosylcobalamin. The consequent functional deficiencies of methylmalonyl-CoA mutase and methionine synthase produce both methylmalonic aciduria and homocystinuria. Systemic symptoms and neurological decompensation comprise the clinical phenotype. In an effort to clarify the phenotype and prognosis, we obtained clinical information on 50 patients with methylmalonic acidaemia whose cells had been assigned to the cblC complementation group. We identified two distinct phenotypes; they differed in age of onset, presence of systemic symptoms, type of neurological symptoms, and outcome after diagnosis and treatment. Forty-four patients presented in the first year of life. Feeding difficulties, neurological dysfunction (hypotonia, seizures, developmental delay), and ophthalmological and haematological abnormalities characterized their clinical picture. About one-quarter of those patients died. Survival was associated with neurological impairment; only one infant was neurologically intact at follow-up. Onset in childhood, in contrast, was associated with less severe haematological abnormalities, largely involving the red cell series. Extrapyramidal signs, dementia, delirium or psychosis characterized the neurological findings. Survival, with mild to moderate disability in some, was typical in patients with later onset. Treatment in both groups included hydroxycobalamin, betaine and carnitine; complete normalization of biochemical parameters was rare.
Key findings
- The clbC form of methylmalonic acidaemia is a rare and poorly understood condition which results from impaired biosynthesis of methylcobalamin and adenosylcobalamin.
- Survival was associated with neurological impairment; only one infant was neurologically intact at follow-up.
- Onset in childhood, in contrast, was associated with less severe haematological abnormalities, largely involving the red cell series.
Study details
- Participants50
- Evidence strengthLow
How this study scored 43/100
Published in a peer-reviewed journal. Scored zero for study design, effect reported and randomised / blinded because the record does not state it. We have no data on journal's citation record, times cited, citations per year, impact for its field and year, cited by studies here, still being cited, senior author's track record, institution's track record and multi-centre collaboration, so those were left out: it earned 25 of the 58 points we could judge it on, which is 43 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Journal of inherited metabolic disease) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 1997 — older than 20 years, still counted |
| Sample size | 1 / 4 | 50 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | — / 7 | No citation count (not found in OpenAlex) — left out of this score |
| Citations per year | — / 5 | No citation count or no year — left out of this score |
| Impact for its field and year | — / 6 | No field-weighted citation impact (OpenAlex has none yet) — left out of this score |
| Cited by studies here | — / 6 | Not yet checked against this library's citation graph — left out of this score |
| Still being cited | — / 4 | No yearly citation counts — left out of this score |
| Senior author's track record | — / 4 | Senior author's record not available — left out of this score |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multi-centre collaboration | — / 3 | Institutions not listed — left out of this score |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 9266389) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 25 / 58 | Scored on 11 of 20 parts. We have no data for the rest, so they are left out: 25 of the 58 points we could judge it on is 43 out of 100. |
| Total | 43 / 100 | — |
What each of these 20 components measures, and what this score is not →
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APA 7th
Rosenblatt, D. S., Aspler, A. L., Shevell, M. I., Pletcher, B. A., Fenton, W. A., & Seashore, M. R. (1997). Clinical heterogeneity and prognosis in combined methylmalonic aciduria and homocystinuria (cblC). Journal of inherited metabolic disease. https://doi.org/10.1023/a:1005353530303
Vancouver
Rosenblatt DS, Aspler AL, Shevell MI, Pletcher BA, Fenton WA, Seashore MR. Clinical heterogeneity and prognosis in combined methylmalonic aciduria and homocystinuria (cblC). Journal of inherited metabolic disease. 1997. doi:10.1023/a:1005353530303. PMID: 9266389.
BibTeX
@article{rosenblatt1997-9266389,
author = {Rosenblatt, D. S. and Aspler, A. L. and Shevell, M. I. and Pletcher, B. A. and Fenton, W. A. and Seashore, M. R.},
title = {{Clinical heterogeneity and prognosis in combined methylmalonic aciduria and homocystinuria (cblC)}},
journal = {Journal of inherited metabolic disease},
year = {1997},
doi = {10.1023/a:1005353530303},
pmid = {9266389},
url = {https://doi.org/10.1023/a:1005353530303}
}
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