Article Text

Findings that shed new light on the possible pathogenesis of a disease or an adverse effect
Deletion of C2orf34, PREPL and SLC3A1 causes atypical hypotonia–cystinuria syndrome
  1. B Chabrol1,
  2. K Martens2,3,
  3. S Meulemans2,
  4. A Cano1,
  5. J Jaeken4,
  6. G Matthijs3,
  7. J W M Creemers2
  1. 1
    Reference Center for inborn metabolic disorders, CHU de la Timone, Marseille, France
  2. 2
    Laboratory for Biochemical Neuroendocrinology, Center for Human Genetics, University of Leuven, Belgium
  3. 3
    Laboratory for Molecular Diagnosis, Center for Human Genetics, University of Leuven, Belgium
  4. 4
    Center for Metabolic Disease, University of Leuven, Belgium
  1. john.creemers{at}


Hypotonia–cystinuria syndrome (HCS) and 2p21 deletion syndrome are two recessive contiguous gene deletion syndromes associated with cystinuria type I. In HCS patients, only SLC3A1 and PREPL are disrupted. In the 2p21 deletion syndrome, two additional genes (C2orf34 and PPM1B) are lost. Molecular analysis of the SLC3A1/PREPL locus was performed in the patients using quantitative polymerase chain reaction (PCR) methods. HCS in both siblings was confirmed with the deletion screen of the SLC3A1/PREPL locus. Fine mapping of the breakpoint revealed a deletion of 77.4 kb, including three genes: SLC3A1, PREPL and C2orf34. Features not present in classical HCS were a mild/moderate mental retardation and a respiratory chain complex IV deficiency. We report the first patients with a deletion of SLC3A1, PREPL and C2orf34. They present with a phenotype intermediate between HCS and 2p21 deletion syndrome.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Competing interests: None.