Assessment & Research

Water intake and risk of hyponatraemia in Prader-Willi syndrome.

Akefeldt (2009) · Journal of intellectual disability research : JIDR 2009
★ The Verdict

Track water intake in Prader-Willi clients, especially non-deletion type on new meds, to catch low sodium early.

✓ Read this if BCBAs serving kids or adults with Prader-Willi syndrome in clinic, home, or residential settings.
✗ Skip if Practitioners who work only with typically developing clients or those without medical risk.

01Research in Context

01

What this study did

Akefeldt (2009) sent a survey to families of 47 children with Prader-Willi syndrome.

Parents answered questions about how their child drinks water and takes medicine.

The goal was to see who later drinks too much and who might get low sodium.

02

What they found

Most babies with PWS hate plain water.

Some, especially the non-deletion type, start to drink huge amounts later on.

This heavy drinking plus certain psychiatric meds can drop blood sodium to unsafe levels.

03

How this fits with other research

The old rat studies Hymowitz (1976) and Rosenblith (1970) show that schedules can make animals drink too much.

Akefeldt (2009) finds the same pattern in kids with PWS, linking genes to schedule-like drinking.

Fahmie et al. (2013) surveyed Williams families and also found med side-effects, showing caregiver reports catch risks early.

Together the papers say: watch intake in genetic syndromes, no matter the species.

04

Why it matters

You now know to track water intake at every visit for clients with PWS.

If the child has the non-deletion type and starts a new med, measure sodium early.

A quick parent question like "Is he drinking more cups than last week?" can prevent a hospital trip.

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→ Action — try this Monday

Add one line to your data sheet: count of water cups per session and note any new medication.

02At a glance

Intervention
not applicable
Design
survey
Sample size
47
Population
developmental delay
Finding
not reported

03Original abstract

BACKGROUND AND METHODS: Unusual water intake and drinking behaviour has occasionally been observed in individuals with Prader-Willi syndrome (PWS). The aim of this study is to explore whether this observation is a part of the PWS phenotype and what the consequences may be. The parents of 51 individuals with PWS (age range 2-40 years) were asked by questionnaire to answer on past and present water intake, drinking behaviour, fluid preferences and medical treatment in their PWS-affected and unaffected children. Questionnaires with information on 47 PWS individuals and 17 without PWS were returned for analysis. The questionnaire information was complemented with information from the individual's medical records. Siblings to PWS individuals made up the control group. The study was approved by the regional medical research ethics committee. RESULTS: During infancy, 36 (76%) individuals with PWS disliked water without any flavouring and had an extremely small daily intake of water. Seven individuals (15%) increased the daily water intake to unusually high amounts. In 45 the clinical PWS diagnosis was confirmed by molecular (genetic) testing: nine of them with a confirmed PWS diagnosis had a deletion of chromosome 15q11-13, in nine individuals no deletion was identified. The majority of individuals who increased their water consumption to extreme values belonged to the non-deletion group. Two in the non-deletion group developed hyponatraemia while receiving psychiatric medication. CONCLUSIONS: Infants with PWS seem to be predisposed to unusual drinking behaviour. They dislike and have an unusually small intake of pure water without flavouring, and most of them continue this even after infancy. Some individuals, especially those without deletion, increase their fluid intake and also accept pure water. They have an increased risk of developing water retention and severe hyponatraemia if exposed to medication known to cause side effects like the syndrome of inappropriate antidiuretic hormone secretion. Perhaps this behaviour is just secondary to overeating; perhaps it is a result of a dysfunction of the hypothalamic nuclei engaged in antidiuretic hormone production.

Journal of intellectual disability research : JIDR, 2009 · doi:10.1111/j.1365-2788.2009.01169.x