I did not realise I had food preferences until I got married. My parents, who are carriers of this condition, also had food preferences, so I used to think that it was normal. My mother’s side of the family has a strong food preference, but only my mother has been tested, so I don’t know if any of them have citrin deficiency. My father’s side of the family does not have very strong preferences and drinks alcohol regularly.

In Japan, citrin deficiency is not classified as an incurable disease unless the patient actually develops symptoms. So even just catching a cold is a huge medical expense for us. If you go to a small clinic nearby, for example, and tell them you have ‘citrin deficiency’, they won’t see you because the doctor doesn’t know what it is in the first place. That’s why you have to go to a university hospital. But then, due to your diagnosis, even if you just have a cold, they conduct all kinds of tests to rule out that the symptoms are being caused by CD. The cost of the tests is many times higher than for people who generally just have a cold. So, I still try to avoid catching colds as much as possible, and although the restrictions on Covid have been eased, I still wear a mask.

My brother was diagnosed with childhood epilepsy and was treated for it all his life. As an adult, my wife and I realised that my brother’s condition did not seem to be epilepsy, and after a ureagenesis test and a detailed examination, it was confirmed he had CTLN2. At that time, his psychological symptoms were showing strongly. When he was born, he could not drink breast milk. As a child he drank non-lactose milk. He had diarrhoea and jaundice, but our parents were not too concerned and when he was about three years old, the symptoms settled down. When he got to primary school, he started having epilepsy.

He was in the printing business and worked day and night, but his tiredness was abnormal. He often fell asleep and did not wake up easily. He was also often angry and very forgetful. But we thought it was normal because our mother, who is a carrier of the disease, and myself are also very forgetful of things. When I married my wife, I realised that was not normal either. He scored reasonably well in school tests, but he had trouble concentrating and listening to others all the way through.

On 29 December 2011, he drank two glasses of alcohol (which he normally did not drink) at an end-of-year party. From that point on, his health started to deteriorate rapidly. Five days later, when my wife and I returned home for New Year’s, we couldn’t understand what he was saying. He spilled milk, couldn’t grab food with chopsticks, and seemed to be constantly drunk even though he hadn’t been drinking. We tried to take him to the hospital, but our mother said there was nothing strange about his behaviour and refused.

A few days later, we spoke to my brother directly and went to the hospital together. We booked an appointment for a brain scan and left that day. However, before the next examination, something strange happened again. He wanted to go to the toilet in the middle of the night and started circling around in his own room and opening the fridge door to turn on the bathroom light. Even then, my mother said he was just sleepwalking and did not call an ambulance.

Mid-January 2012, he went to the hospital again for his brain scan. When he returned home, he got sick and was taken back to the hospital by ambulance. He was suspected to have hyperammonaemia, so he was given a high-concentration transfusion without any explanation to us. About 30 minutes to an hour later, he fell into a coma. I still don’t know what the infusion was at that time, but we assume that is what put him in a coma. We weren’t convinced that the cause was just hyperammonaemia and asked for another test. That’s when he got a confirmed diagnosis of citrin deficiency.

After that, he repeatedly woke up and went into a coma until his passing. When we found out that he had citrin deficiency, his liver was already in a terminal state and was told that a liver transplant was the only option. We prepared for a transplant, but it was difficult to find a donor.

He was referred to Shinshu University. This was in March 2012. He was given arginine and managed his diet while waiting for a liver transplant donor to be found. There was a suggestion to put a lock on the fridge, but we did not go that far. However, there were times when he would open the fridge and eat whatever was in there. It seemed that he was eating unconsciously without realising. That summer, we were told that there was nothing more they could do for him, and he was referred to a hospital for his final end-of-life care. Within a month after his transfer, he passed away.

Before he died, he said that he wanted his body to be used for research into citrin deficiency if it would help future children. So, the samples are still being stored. I am sure he is happy about the establishment of Citrin Foundation too.