The study has shown that the strengthening program applied to the families of children diagnosed with phenylketonuria (PKU) and the education given; It will be conducted in order to examine the effect of the family's coping attitudes, knowledge scores about the disease and its management. The research is of the randomized controlled experimental type. Children from PKU constitute the universe in the city center of Van. The families of children between the ages of 0-3 who were diagnosed with PKU will form the sample of the study. A nursing strengthening program will be applied to families in the experimental group for 10 weeks. The scope of this program; It consists of face-to-face training on disease management, giving the educational guide (booklet) for the families of babies diagnosed with PKU, telephone calls during the education process and counseling services. No application will be made to the families in the control group. After the application of the last tests to the control group; Face-to-face training and a booklet will be given to the experimental group. Data; It will be collected with 'Child and Family Introductory Information Form', 'Parents' Information Level Assessment Form about Phenylketonuria' and 'Coping Attitudes Assessment Scale'.

In the literature, there is no study showing the effect of the education given to the families of babies diagnosed with PKU on their coping attitudes. Based on the need to fill this knowledge gap in the literature, it is thought that the study will contribute to the field of child health and disease nursing.

Phenylketonuria is a disorder of phenylalanine metabolism and causes intellectual destruction if left untreated. It is an autosomal recessive metabolic disease that develops as a result of the absence of the enzyme phenylalanine hydroxylase (FAH), which provides the necessary amino acid metabolism for protein production in the body, which causes high phenylalanine in the blood. In our country, it is one of the places where PKU is commonly encountered (Çavuşoğlu, 2015; Hafid et al, 2015; Törner and Büyükgönenç, 2013). While the incidence of this disease in European countries is 1/10000-30000, it is 1/3000-4500 in our country (Alparslan, 2021). This situation is directly related to consanguineous marriages. It is stated that one out of every five marriages in our country is consanguineous marriage. If left untreated, it can cause extreme mental retardation, convulsions and death (Alparslan, 2021; Çavuşoğlu, 2015; Hafid et al, 2015; Törner and Büyükgönenç, 2013).

The care of the child with phenylketonuria is carried out by the parents. Extra care (diet therapy, control of blood phenylalanine level, etc.) for children in this diagnosis group is provided by their parents. The treatment and care process of children with PKU affects family routines, relationships and parenting styles. Parents of children experience emotional and economic burden. Therefore, it is stated that the care burden of parents in this diagnosis group is higher than that of healthy parents, and their quality of life is lower (Hatzmann et al, 2009). In addition, studies have shown that families of children with PKU have high levels of anxiety, depression (Mahmoudi-Gharaei et al. 2011) and stress (Irannejad et al. 2018). In another study; It is reported that the family's routines have changed (not eating in front of the child, not eating in restaurants, etc.) and that they experience anxiety about the effect of diet incompatibility on blood phenylalanine levels, feeling overwhelmed and guilt in the care process (Carpenter et al 2018). Therefore, having a child with PKU may affect coping attitudes.

Child health and diseases nurse should support children with PKU and their families on issues such as informing, training and counseling about the disease and its management.

Inclusion Criteria:

• Residing in Van and/or being followed up in the pediatric metabolism polyclinic,
• Agreeing to participate in the research,
• literate,
• Speaking and understanding Turkish,
• 18 years old and over
• Fully oriented and cooperative and open to communication,
• a parent who is the primary caregiver of the child,
• The child is in the 0-3 age range (≤3 years old),
• Families of children with definitive diagnosis of PKU will be included.

Exclusion Criteria:

• Not residing in Van and/or not being followed up in the pediatric metabolism polyclinic,
• Those who do not accept to participate in the research, who are illiterate,
• Does not speak or understand Turkish,
• Parent/family member who is aged 17 or younger, who is not fully oriented and cooperative and not open to communication, and does not provide primary care for the child,
• The child is over 3 years old (3 years <),
• Dropping out of the training to be applied,
• Families of children with PKU who are not definitively diagnosed will not be included in the study.