Dietary management and growth outcomes in children with propionic acidemia: A natural history study.

Background: Propionic acidemia (PROP) is an autosomal recessive inherited deficiency of propionyl-CoA carboxylase (PCC) which is involved in the catalytic breakdown of the amino acids valine, isoleucine, methionine, and threonine. PROP nutritional management is based on dietary protein restriction and use of special medical formulas which are free of the offending amino acids, but are enriched in leucine. The resulting imbalance among branched-chain amino acids negatively impacts plasma concentrations of valine and isoleucine, which might impact growth in children with PROP.

Morquio-B disease: Clinical and genetic characteristics of a distinct -related dysostosis multiplex.

Background: Morquio-B disease (MBD) is a distinct -related dysostosis multiplex involving the trabecular parts of long bones and spine, presenting a mild phenocopy of -related Morquio-A disease.

Methods: We analyzed 63 (n = 62 published) cases with MBD to describe their clinical, biochemical and genetic features.

Results: Forty-one of 51 cases with informative clinical data had including progressive growth impairment, kyphoscoliosis, coxa/genua valga, joint laxity, platyspondyly, odontoid hypoplasia.