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Abstract: A 1-year-old child was found to have abnormally elevated citrulline on postnatal heel blood screening, but liver function and other blood chemistries were normal. At the age of 1 week, the child’s growth and development were normal, and the blood citrulline was still higher than normal on reexamination, and the genetic test result was citrullinemia type I. After dietary guidance and medication, the child’s blood ammonia and liver function indexes were normal at the time of review, but he still needed to adhere to treatment and review.
Basic information】Female, 1 year old
Disease Type】Citrullinemia
Hospital】The Second Hospital of Harbin Medical University
Date of Consultation】January 2022
Treatment plan】Low protein diet + galactose milk powder + medication (levocanidine oral solution + vitamin D3 drops + multivitamin zinc)
【Treatment period】Lifetime treatment, now treatment for six months, then review every 3-6 months
【Treatment effect】Normal growth and development, normal liver function
I. Initial consultation
The parents described that the child was born at term, with a birth weight of 3080g and a length of 50cm, and a postnatal heel blood screening test found abnormal guanine. However, the child’s liver function and other blood test indicators were normal, so the family did not pay attention to the child, and the doctor recommended regular rechecking. The family did not take the child for review. Now the child is 1 week old, with normal growth and development, and the family did not find any abnormalities in the child. The family did not find any abnormality in the child. The blood citrulline was still higher than normal and doubled compared to the birth.
In order to further clarify the diagnosis, the family was advised to perform genetic testing, and the results considered the child to have citrullinemia type I, a heterozygous mutation. The disease can cause abnormal liver function, so the child was also retested for liver function and blood ammonia, as well as a detailed evaluation of the child’s neurological development, all of which were within normal limits.
This is a very rare genetic metabolic disease that can cause developmental delay, liver function abnormalities, intellectual and motor abnormalities, and has a high mortality and disability rate. The child’s current test results are normal. It is considered that the symptoms are mild because the child is heterozygous for the mutation, and that the child may have a late onset of the disease.
Treatment
Since citrullinemia is a very rare genetic metabolic disease, there is no specific clinical treatment for it. Therefore, on the one hand, we should strictly manage the child’s diet, try to limit the protein diet to avoid elevated blood ammonia, and minimize the entry of citrulline into the body to avoid the damage to the nervous system caused by elevated blood ammonia. At the same time, we should pay attention to the supplementation of glucose and various electrolytes, and let the child eat galactose milk powder to ensure that the child needs all kinds of energy for growth and development. In terms of medication, the child is advised to take oral levocaine solution, as well as some fat-soluble vitamins, such as vitamin D3 drops, and trace elements, such as zinc multivitamin. The child’s family was also instructed to treat the child for life and to check liver function and blood ammonia every 3-6 months afterwards.
III. Treatment effect
Citrullinemia is a very rare genetic metabolic disorder. The child underwent 6 months of systematic medication, while the parents actively cooperated with the treatment by supervising the child’s daily life, strictly controlling the diet, limiting protein intake, and especially avoiding foods that may contain citrulline as much as possible. The child’s liver function and blood ammonia were checked every 3-6 months, and neurological evaluation was also performed. Now the child has been treated for six months and all indicators are in the normal range.
IV. Precautions
Since children with citrullinemia have a specific enzyme synthesis disorder that causes citrulline to accumulate easily in the body, resulting in abnormal liver function and neurological symptoms, the child’s family should pay special attention to the daily diet, strictly control the diet, limit protein intake, and especially try to avoid foods that may contain citrulline. Observe the child’s symptoms and regularly review the liver function and blood ammonia. If the blood ammonia rises sharply, hemodialysis should be performed in time to avoid life-threatening conditions. I also talked to the parents about the disease at a later stage, and the parents were relieved to know that the child was in good condition and had been regularly reviewed.
V. Personal insight
Citrullinemia is a very rare genetic metabolic disease. Therefore, in the early stage of the disease, when the child does not have any uncomfortable symptoms, it is very easy to be ignored by parents, as in this case. Parents are reminded that if their child has any abnormal indicators in the examination, they must pay attention to it and try to have a review to find out the cause so as to avoid any missed diagnosis and delayed treatment.