10 January 2012 - Merck Serono, a unit of Germany's Merck KGaA (ETR:MRK), said on Tuesday that it had enrolled the first patient in the validation study for the first quality-of-life questionnaire specific to phenylketonuria (PKU-QOL questionnaire).

The validation study is the last stage in the development of this questionnaire, which is created to allow the medical community to measure the impact of the disease and its treatment on the quality of life of PKU patients and their parents.

The multi-centre, prospective, observational study will be conducted at over 30 sites in seven countries. Nearly 550 patients from three age groups of PKU patients and a group of parents/caregivers of PKU patients will be enrolled in the study to validate the four age-specific versions of the PKU-QOL questionnaire.

Healthcare professionals are expected to receive the first PKU-QOL questionnaires in seven languages in early-2013.