Dietary practices in methylmalonic acidaemia: a European survey
Authors: Pinto Alex , Evans Sharon , Daly Anne , Almeida Manuela Ferreira , Assoun Murielle , Belanger-Quintana Amaya , Bernabei Silvia Maria , Bollhalder Sandra , Cassiman David , Champion Helena , Chan Heidi , Corthouts Karen , Dalmau Jaime , Boer Foekje de , Laet Corinne De , Meyer An de , Desloovere An , Dianin Alice , Dixon Marjorie , Dokoupil Katharina , Dubois Sandrine , Eyskens Francois , Faria Ana , Fasan Ilaria , Favre Elisabeth , Feillet François , Fekete Anna , Gallo Giorgia , Gingell Cerys , Gribben Joanna , Hansen Kit Kaalund , Horst Nienke Ter , Jankowski Camille , Janssen-Regelink Renske , Jones Ilana , Jouault Catherine , Kahrs Gudrun Elise , Kok Irene , Kowalik Agnieszka , Laguerre Catherine , Verge Sandrine Le , Liguori Alessandra , Lilje Rina , Maddalon Cornelia , Mayr Doris , Meyer Uta , Micciche Avril , Och Ulrike , Robert Martine , Rocha Júlio César , Rogozinski Hazel , Rohde Carmen , Ross Kathleen , Saruggia Isabelle , Schlune Andrea , Singleton Kath , Sjoqvist Elisabeth , Skeath Rachel , Stolen Linn Helene , Terry Allyson , Timmer Corrie , Tomlinson Lyndsey , Tooke Alison , Kerckhove Kristel Vande , van Dam Esther , Hurk Dorine van den , Ploeg Liesbeth van der , van Driessche Marleen , van Rijn Margreet , Wegberg Annemiek van , Vasconcelos Carla , Vestergaard Helle , Vitoria Isidro , Webster Diana , White Fiona , White Lucy , Zweers Heidi , MacDonald Anita 
Published: December 2019

Abstract

Background
The dietary management of methylmalonic acidaemia (MMA) is a low-protein diet providing sufficient energy to avoid catabolism and to limit production of methylmalonic acid. The goal is to achieve normal growth, good nutritional status and the maintenance of metabolic stability.

Aim
To describe the dietary management of patients with MMA across Europe.

Methods
A cross-sectional questionnaire was sent to European colleagues managing inherited metabolic disorders (IMDs) (n=53) with 27 questions about the nutritional management of organic acidaemias. Data were analysed by different age ranges (0–6 months; 7–12 months; 1–10 years; 11–16 years; >16 years).

Results
Questionnaires were returned from 53 centres. Twenty-five centres cared for 80 patients with MMA vitamin B12 responsive (MMAB12r) and 43 centres managed 215 patients with MMA vitamin B12 non-responsive (MMAB12nr). For MMAB12r patients, 44% of centres (n=11/25) prescribed natural protein below the World Health Organization/Food and Agriculture Organization/United Nations University (WHO/FAO/UNU) 2007 safe levels of protein intake in at least one age range. Precursor-free amino acids (PFAA) were prescribed by 40% of centres (10/25) caring for 36% (29/80) of all the patients. For MMAB12nr patients, 72% of centres (n=31/43) prescribed natural protein below the safe levels of protein intake (WHO/FAO/UNU 2007) in at least one age range. PFAA were prescribed by 77% of centres (n=33/43) managing 81% (n=174/215) of patients. In MMAB12nr patients, 90 (42%) required tube feeding: 25 via a nasogastric tube and 65 via a gastrostomy.

Conclusions
A high percentage of centres used PFAA in MMA patients together with a protein prescription that provided less than the safe levels of natural protein intake. However, there was inconsistent practices across Europe. Long-term efficacy studies are needed to study patient outcome when using PFAA with different severities of natural protein restrictions in patients with MMA to guide future practice.