Disorder | Type of disorder (PBD versus single enzyme deficiency) | Gene(s) involved | Clinical features | Age at presentation | Radiographic findings | Initial diagnostic biochemical test | Confirmatory tests | Treatment |
Zellweger spectrum disorders (ZSD)* | PBD | PEX1 PEX6 Other PEX genes (uncommon) |
| Variable; severe forms present in newborn period |
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ACOX1 deficiency | Enzyme deficiency | ACOX1 |
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DBP deficiency | Enzyme deficiency | HSD17B4 |
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Rhizomelic chondrodysplasia punctata (RCDP) | PBD (RCDP types 1 and 5) Enzyme deficiency (RCDP types 2, 3, and 4) | RCDP type 1: PEX7 RCDP type 2: GNPAT RCDP type 3: AGPS RCDP type 4: FAR1 RCDP type 5: PEX5 |
| Variable; severe forms present in newborn period |
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Refsum disease | Enzyme deficiency | PHYH |
| Adolescence or early adulthood |
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ACBD5: acyl-CoA-binding domain type 5; ACOX1: Acyl CoA oxidase-1; ACOX2: Acyl CoA oxidase-2; AMACR: 2 methylacyl-CoA racemase; BAAT: bile acid-CoA: amino acid N-acyltransferase; C26:0-LPC: C26:0-lysophosphatidylcholine; DBP: D-bifunctional protein; MRI: magnetic resonance imaging; PBD: peroxisome biogenesis disorder; PMP70: peroxisomal membrane protein 70; SCPX: sterol carrier protein-X; VLCFA: very long-chain fatty acid; VUS: variant of uncertain significance; ZSD: Zellweger spectrum disorders.
* ZSD represents a spectrum of disorders that includes classical Zellweger syndrome (the most severe form) and other milder variants. Some conditions included in this category were previously considered separate disorders (eg, neonatal adrenoleukodystophy [NALD] and infantile Refsum disease [IRD]). However, since NALD and IRD are caused by the same genetic variants as ZSD (PEX1 and PEX6) with a similar constellation of clinical and laboratory findings, they are now considered part of ZSD.
¶ If plasma C26:0-LPC or VLCFA analysis is abnormal, additional testing is performed in the same blood sample, including analysis of peroxisomal biomarkers in plasma (bile acid intermediates, phytanic acid, pristanic acid, pipecolic acid) and peroxisomal biomarkers in erythrocytes (plasmalogens).
Δ Additional confirmatory testing with functional assays using fibroblasts can sometimes be useful in the diagnostic evaluation for these disorders (eg, if genetic testing identifies a VUS).آیا می خواهید مدیلیب را به صفحه اصلی خود اضافه کنید؟