Rare Saposin A deficiency: Novel variant and psychosine analysis.
Mol Genet Metab
; 129(2): 161-164, 2020 02.
Article
en En
| MEDLINE
| ID: mdl-31439510
ABSTRACT
Saposin A is a post-translation product of the prosaposin (PSAP) gene that serves as an activator protein of the galactocerebrosidase (GALC) enzyme, and is necessary for the degradation of certain glycosphingolipids. Deficiency of saposin A leads to a clinical picture identical to that of early-infantile Krabbe disease caused by GALC enzyme deficiency. Galactosylsphingosine, also known as psychosine, is a substrate of the GALC enzyme that is known to be elevated in classic Krabbe disease. We present the case of an 18-month-old male with clinical and radiological findings concerning for Krabbe disease who had preserved GALC enzyme activity and negative GALC gene sequencing, but was found to have a homozygous variant, c.257â¯Tâ¯>â¯A (p.I86N), in the saposin A peptide of PSAP. Psychosine determination on dried blood spot at 18â¯months of age was elevated to 12â¯nmol/L (normal <3â¯nmol/L). We present this case to add to the literature on the rare diagnosis of atypical Krabbe disease due to saposin A deficiency, to report a novel presumed pathogenic variant within PSAP, and to suggest that individuals with saposin A deficiency may have elevated levels of psychosine, similar to children with classic Krabbe disease due to GALC deficiency.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Psicosina
/
Saposinas
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Galactosilceramidasa
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Homocigoto
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Leucodistrofia de Células Globoides
Límite:
Humans
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Infant
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Male
Idioma:
En
Revista:
Mol Genet Metab
Asunto de la revista:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
/
METABOLISMO
Año:
2020
Tipo del documento:
Article