Involvement of hyperprolinemia in cognitive and psychiatric features of the 22q11 deletion syndrome.
Microdeletions of the 22q11 region, responsible for the velo-cardio-facial syndrome (VCFS), are associated with an increased risk for psychosis and mental retardation. Recently, it has been shown in a hyperprolinemic mouse model that an interaction between two genes localized in the hemideleted region, proline dehydrogenase (PRODH) and catechol-o-methyl-transferase (COMT), could be involved in this phenotype. Here, we further characterize in eight children the molecular basis of type I hyperprolinemia (HPI), a recessive disorder resulting from reduced activity of proline dehydrogenase (POX). We show that these patients present with mental retardation, epilepsy and, in some cases, psychiatric features. We next report that, among 92 adult or adolescent VCFS subjects, a subset of patients with severe hyperprolinemia has a phenotype distinguishable from that of other VCFS patients and reminiscent of HPI. Forward stepwise multiple regression analysis selected hyperprolinemia, psychosis and COMT genotype as independent variables influencing IQ in the whole VCFS sample. An inverse correlation between plasma proline level and IQ was found. In addition, as predicted from the mouse model, hyperprolinemic VCFS subjects bearing the Met-COMT low activity allele are at risk for psychosis (OR = 2.8, 95% CI = 1.04-7.4). Finally, from the extensive analysis of the PRODH gene coding sequence variations, it is predicted that POX residual activity in the 0-30% range results into HPI, whereas residual activity in the 30-50% range is associated either with normal plasma proline levels or with mild-to-moderate hyperprolinemia.
Raux
Grégory
G
Department of Genetics and Inserm U614, IFRMP, Faculty of Medicine, Rouen, France.
Bumsel
Emilie
E
Hecketsweiler
Bernadette
B
van Amelsvoort
Therese
T
Zinkstok
Janneke
J
Manouvrier-Hanu
Sylvie
S
Fantini
Carole
C
Brévière
Georges-Marie M
GM
Di Rosa
Gabriella
G
Pustorino
Giuseppina
G
Vogels
Annick
A
Swillen
Ann
A
Legallic
Solenn
S
Bou
Jacqueline
J
Opolczynski
Gaelle
G
Drouin-Garraud
Valérie
V
Lemarchand
Marie
M
Philip
Nicole
N
Gérard-Desplanches
Aude
A
Carlier
Michèle
M
Philippe
Anne
A
Nolen
Marie Christine
MC
Heron
Delphine
D
Sarda
Pierre
P
Lacombe
Didier
D
Coizet
Cyril
C
Alembik
Yves
Y
Layet
Valérie
V
Afenjar
Alexandra
A
Hannequin
Didier
D
Demily
Caroline
C
Petit
Michel
M
Thibaut
Florence
F
Frebourg
Thierry
T
Campion
Dominique
D
D000293:Adolescent; D000328:Adult; D000483:Alleles; D002394:Catechol O-Methyltransferase / Q000235:genetics; D002872:Chromosome Deletion; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics*; D004062:DiGeorge Syndrome / Q000235:genetics / Q000523:psychology*; D004827:Epilepsy / Q000097:blood / Q000201:enzymology / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008607:Intellectual Disability / Q000097:blood / Q000201:enzymology / Q000235:genetics; D008297:Male; D008715:Methionine / Q000235:genetics; D008875:Middle Aged; D010641:Phenotype; D011392:Proline / Q000097:blood* / Q000235:genetics; D011394:Proline Oxidase / Q000235:genetics*; D011618:Psychotic Disorders / Q000097:blood / Q000201:enzymology / Q000235:genetics; D012307:Risk Factors
D011392:Proline; D008715:Methionine; D011394:Proline Oxidase; D002394:Catechol O-Methyltransferase