Involvement of hyperprolinemia in cognitive and psychiatric features of the 22q11 deletion syndrome

Gregory Raux , Emilie Bumsel , Bernadette Hecketsweiler , Therese Van Amelsvoort , Janneke Zinkstok , Sylvie Manouvrier-Hanu (1) , Carole Fantini (2) , Georges-Marie M. Breviere , Gabriella Di Rosa (3) , Giuseppina Pustorino , Annick Vogels , Ann Swillen , Solenn Legallic (4) , Jacqueline Bou , Gaelle Opolczynski , Valérie Drouin-Garraud (5) , Marie Lemarchand , Nicole Philip (6) , Aude Gerard-Desplanches , Michèle Carlier (7) , Anne Philippe (8) , Marie Christine Nolen , Delphine Heron (9) , Pierre Sarda (10) , Didier Lacombe (11) , Cyril Coizet , Yves Alembik (12) , Valérie Layet (13) , Alexandra Afenjar (14) , Didier Hannequin (4, 15, 16) , Caroline Demily (17) , Michel Petit (18) , Florence Thibaut (19) , Thierry Frebourg (4, 16) , Dominique Campion (4)

1 Laboratoire de Génétique Clinique
2 ULB - Université libre de Bruxelles
3 Department of Medical and Surgical Pediatrics
4 Génétique médicale et fonctionnelle du cancer et des maladies neuropsychiatriques
5 Service de génétique [Rouen]
6 Département de génétique médicale [Hôpital de la Timone - APHM]
7 LPC - Laboratoire de psychologie cognitive
8 LMJL - Laboratoire de Mathématiques Jean Leray
9 CHU Pitié-Salpêtrière [AP-HP]
10 Service de Génétique
11 Service de génétique médicale
12 Department of Medical Genetics
13 Unité de Cytogénétique et Génétique Médicale
14 CHU Trousseau [APHP]
15 Service de neurologie [Rouen]
16 Department of Genetics
17 centre hospitalier St-Jean-de-Dieu
18 CIHEAM - Centre International de Hautes Études Agronomiques Méditerranéennes
19 Unité de Psychiatrie CHU C Nicolle

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.

Domaines: Psychologie

Gregory Raux, Emilie Bumsel, Bernadette Hecketsweiler, Therese Van Amelsvoort, Janneke Zinkstok, et al.. Involvement of hyperprolinemia in cognitive and psychiatric features of the 22q11 deletion syndrome. Human Molecular Genetics, 2007, 16 (1), pp.83-91. ⟨10.1093/hmg/ddl443⟩. ⟨hal-01440622⟩