Assessing Phenylalanine Blood Level in Children Having Phenylketonuria in Southern Khorasan Province, and Determining the Affecting Social and Demographic Factors

Background: Phenylketonuria is a metabolic disorder resulting from a defect in phenylalanine metabolism with a global prevalence of 1 in 10000. Delayed initiation of dietary modication leads to brain injury and cognitive and behavioral problems. The main objective of this study was to assess the demographic and social factors affecting metabolic control of patients having phenylketonuria in Southern Khorasan Province. Methods: In this cross-sectional descriptive analytic study which was performed during summer 2019, 32 out of 37 known children and adolescents having phenylketonuria in Southern Khorasan Province were assessed. The age of patients, the gender of patients, parents maritalstatus,parents occupational status, parents` educational level, the distance between home and phenylketonuria clinic, and the number of affected siblings having phenylketonuria were documented. We were not able to contact ve patients having phenylketonuria in Southern Khorasan Province. Data were analyzed by SPSS 16 software using Mann-Whitney U test and Kruskal-Wallis test. The signicance level was considered as p <0.05. Results: 32 patients with a mean age of 6.6±4.7 years were enrolled in this study. 23 of them were male (71.9%) and 9 patients were females (28.1%). The mean phenylalanine level in this study group was 8.1±5.2 mg/dl. The disease was optimally controlled in 14 patients (43.3%) and poorly controlled in 18 of them (56.3%). There was not any statistically signicant relation between the metabolic control of the disease and any of the assessed social and demographic factors. Conclusion: The disease was properly controlled in 43.3% of the assessed population, and 56.3% had poor metabolic control. There was not any statistically signicant relation between the metabolic control of patients having phenylketonuria in Southern Khorasan Province and assessed demographic and social. As the number of known cases in South Khorasan province is limited, small sample size could be one of the main limitations of our study.

Assessing possible factors that might affect patients adherence → thetherapeuticdietcod ̲ beanimp or tantprogress ∈ aχev ∈ gbeercaref or them. A or d ∈ g → asystematicreviewartic ≤ byMe educational level, child knowledge about phenylketonuria, parent employment or occupational status, and the number of siblings with phenylketonuria are factors that have signi cant positive correlation with phenylalanine blood level. The authors of this review article state that there is a paucity of studies examining the potential demographic or psychosocial in uences on metabolic control of patients having phenylketonuria, which could be due to the rarity of this disease and small sampling pool. [7] In 2011 during a study performed on 105 children having phenylketonuria at Mo d hospital, Tehran, the following factors were found to be correlated with the metabolic control of these patients. Metabolic control was better in those under 12 years old. The number of siblings having phenylketonuria, divorced parents, and occupational status of parents were among other affecting factors. The authors concluded that the social status of patients affect phenylalanine level to some degree. [18] In a study performed by Mahmoudi-Gharaei et al., 49 care givers of children having phenylketonuria who were presented to a psychiatry outpatient clinic were assessed. Based on the results of this study, 57.1 per cent and 50.1 percent of caregivers had depression and anxiety respectively; and employment status played a meaning full role regarding their mental health. The authors recommended performing similar studies in other parts of Iran. [19] Considering the lack of similar studies in the eastern part of Iran, this study was conducted to assess the effect of a number of suggested socioeconomic factors that are presumed to be correlated with phenylalanine blood level.

2-Methods
This is a cross-sectional descriptive analytic study which was conducted in summer 2019 in South Khorasan Province, Iran. 32 out of 37 known children and adolescents having phenylketonuria in Southern Khorasan Province were assessed.

2-1. Inclusion Criteria
The main inclusion criteria were as follow: Living in south Khorasan province To be under 18 years of age

2-2. Exclusion Criteria
The main exclusion criteria were as follow: The dissatisfaction of the patient or legal guardian for participation in the research 2-3. Sample Size: There were 37 known cases of phenylketonuria under 18 years old at time of performing this study in South Khorasan province. 32 patients and their families were thoroughly interviewed and assessed; it was not possible to contact ve cases, so the sample size was 32.

2-4. Method
Age, sex, family composition factors including separated parents or cohabitant parents, occupational status of parents, living in Birjand city were the phenylketonuria clinic is located or living out of Birjand city, and the number of siblings having phenylketonuria were the socioeconomic factors that were assessed among children and adolescence having phenylketonuria in South Khorasan province, and the relation of these factors with metabolic control of the disease were assessed. It must be noted that Birjand is the capital of South Khorasan Province.
Data was gathered during regular and periodic visits of patients at the main phenylketonuria clinic of South Khorasan province, in Valieasr hospital. In order to assess the metabolic control of patients, the mean blood phenylalanine of patients was also recorded. According to the Iranian National Phenylketonuria guideline, the acceptable blood phenylalanine level of patients aged below 12 years old, and those above 12 years old are 2-6 mg/dl and 2-10 mg/dl respectively; a mean blood phenylalanine blood level above the mentioned values is indicative of poor metabolic control.

2-5. Data Analysis
Data were analyzed using the SPSS software version 22.0 using the Kolmogorov-Smirnov test to show the normal distribution of data. As blood phenylalanine level was not normally distributed (p = 0.007), Mann-Whitney U Test and Kruskal Wallis Test were used to compare the mean phenylalanine blood level of patients based on their demographic and socioeconomic condition. A p-value of less than 0.05 was considered a statically signi cant difference.

3-Results
32 patients with a mean age of 6.6 ± 4.7 years old were enrolled in this study; the lowest recorded age was one year old and the highest was 18 years old. 71.9 per cent of patients were male. The demographic characteristics of patients and their families are presented in Table-1. The mean blood phenylalanine level was 8.1 ± 5.2 mg/dl. The minimum and maximum blood phenylalanine levels were 0.4 mg/dl and 21.4 mg/dl respectively.
According to the data presented in table 2, none of the assessed demographic and social factors were statistically related to blood phenylalanine level. Table-2 Comparison of blood phenylalanine level based on social and demographic characteristics of patient Although there are differences between the blood phenylalanine level of patients with different demographic and social characteristics, but the differences are not statistically signi cant.
As depicted in Fig. 1, the metabolic control of 14 patients (43.3%) was acceptable, and 18 patients (56.3%) had poorly controlled blood phenylalanine levels. Table 3 presents comparison of the metabolic control of patients based on their social and demographic characteristics.

4-Discussion
According to the study performed by Hartnett et al. in 2013, there was not any statistically meaningful relation between patient age and blood phenylalanine level, which is similar to the result of our study (20). On the other hand, based on a study performed by Cotugno et al. in 2011, patient age and the metabolic control of the disease are statistically related, and those over 10 years old have better metabolic control (21). As a rule, older patients are better oriented regarding the importance of appropriate diet and potential complications of poor metabolic control. In order to nd the cause of lack of relation between age and metabolic control in our study, the history of national phenylketonuria screening program in Iran must be considered. The national phenylketonuria screening program in Iran has been started since 2012; and our study was performed in 2019. In our study, children who have been screened by the national phenylketonuria screening program were 8 years old or younger; and children older than 8 years old have not been screened. Delayed diagnosis of phenylketonuria in those over 8 years old is usually associated with negative effects on cognitive and intellectual abilities of these children, which could account for the lack of good metabolic control among older individuals. Based on the results of our study, the metabolic control of patients living in Birjand, the capital of South Khorasan province, is the same as those living out of Birjand; the lack of difference between the two groups of patients could be due to expansion of healthcare centers across the province.
According to the study performed by Alaei M et al. in 2011 the metabolic control of the disease was negatively affected by the number of affected siblings having PKU; on the other hand, based on the results of our study these two factors are not statistically related (18). Having more than one affected child could be both a nancial and psychiatric burden; but as mentioned above, improved healthcare system and insurances have probably reduced the effects of these factors.

4.1-Limitations
As the number of known cases in South Khorasan province is limited, small sample size could be one of the main limitations of our study.
We also believe that there could be other possible socioeconomic and psychiatric factors that might affect blood phenylalanine level in patients having phenylketonuria.

5-Conclusion
Demographic and social factors including age, gender, parentsmaritalstatus, parents occupational status, the distance between home and phenylketonuria clinic (living in Birjand city or living outside Birjand city), and the number of affected siblings having phenylketonuria were not statistically related to metabolic control of disease in patient having phenylketonuria is South Khorasan province. Parents or legal guardians' informed consent was obtained before participation in the study. The aim of the present study was also explained to the patients' parents or legal guardian. Participation in this study imposed no costs on patients.

6.2-Consent for publication
Consent for publication was also obtained from parents or legal guardians.

6.3-Availability of data and material
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

6.4-Competing interests
The authors declare that they have no competing interests.

6.5-Funding
This study did not receive any funding or nancial support.
6.6-Authors contribution TC designed the study and supervised all steps of this study; she is also the chief manager of phenylketonuria clinic in South Khorasan Province. BB performed the data analysis and interpreted data. EA and SS gathered the data through personal interviews and assessing the documents. NH was responsible for literature review; she also played a role in designing the study, and wrote the manuscript. All authors read and approved the nal manuscript.