Various tests revealed that Teodorek had a smaller head circumference (microcephaly), persistent neonatal reflexes, central hypotonic syndrome, hypothyroidism, and suspected congenital visual impairment (CVI). As a result, his development was not progressing as it should. Samples were also taken for genetic testing and screening for metabolic disorders, but all tests returned negative. When Teo was one year old, he underwent an MRI of his brain, which revealed minor morphological changes: a smaller corpus callosum and hypoplasia of the frontal lobes. The cause of his developmental delay was identified as a congenital brain malformation of unclear etiology. At the age of two, a follow-up MRI scan of his brain showed stationary findings, and at that time, neurologists suspected autism. However, due to Teo's young mental age, this diagnosis was not confirmed. When Teo turned four, he began to stagnate not only in his development but also in his growth and weight gain. Still, without a diagnosis, we were referred to the Outpatient Clinic for Undiagnosed Pediatric Patients under Katerina Slaba, M.D., Ph.D.
Thanks to this, Teo underwent further tests, including more detailed genetic testing and screenings for metabolic disorders, but still without any findings. The most recent MRI, conducted when Teo had just turned 5, showed that his brain was normal, ruling out a congenital brain malformation from the diagnosis. During his hospitalization at the pediatric neurology department, Teo underwent muscle and skin tissue biopsies, and we are still awaiting the results. In terms of development, Teo started crawling at 15 months, stood up by himself using furniture for support at 20 months, and took a few steps without support over time. However, he still does not walk independently and is mentally at the level of an 8-month-old baby. Teo’s slow progress has been achieved primarily thanks to intensive therapy. Teo has been using the Vojta method since he was 4 months old. Later, we moved on to the Bobath method and Feldenkrais therapy. We also attend neurorehabilitation clinics, hippotherapy, craniosacral therapy, sensory therapy, specialised speech therapy focused on alternative forms of communication, and occupational therapy. Currently, Teodor is 5.5 years old and is able to stand independently for a short time, climb on the couch, and get up where he needs to.
Teo moves mainly by crawling. Independent walking is still lacking as he struggles to maintain his balance. He communicates using gestures, pointing to food and drink. For now, he doesn’t require many more gestures for communication, but he has started pointing to familiar people and animals and recognizing familiar objects and people in photos. He is particularly interested in musical toys, spinners, and car wheels. He enjoys sound books and is completely fascinated by water. Teo reacts very badly to common childhood viral infections, with his body’s response being vomiting. Because of this, he has been hospitalized three times at the University Hospital in Brno due to dehydration and internal imbalance. However, the last hospitalisation in the Intensive Care Unit (ICU) with the infectious disease ICU had a positive outcome. Thanks to his stay in the ICU, Teo was included in the “BabyFox” project at the Center for Precision Medicine and the Outpatient Clinic for Pediatric Patients at the University Hospital Brno, where whole-genome sequencing was performed. After 5.5 years of examinations, hospitalisations, screenings, and tests, we finally learned the cause of Teo’s condition: an RNU4-2 mutation on chromosome 12, known as ReNU syndrome, which was first described in April 2024.
Despite being a newly discovered mutation, there are quite a few children with this syndrome, and they all share similar characteristics to Teo: significant developmental delay, severe intellectual disability, lack of speech, and short stature. However, they are also very cheerful children who love music, light, and musical toys and are fascinated by water – just like our Teodor. After receiving the diagnosis, we felt a great relief as parents. We finally know the cause of Teo’s condition and, most importantly, how he can progress and how far he can go. We know that with regular therapy, Teo will likely be able to walk independently and that he can learn to communicate in alternative ways. Thanks to the diagnosis, we have also connected with other parents through the Facebook group "RNU4-2/ReNU Syndrome Family Connect," which currently has 300 members, mainly parents of children from the USA, the UK, France, and Spain. Through this group, we learn more about ReNU syndrome and hear the stories of other families and patients with this diagnosis. In July 2025, the first conference on ReNU syndrome will take place in New York, which we plan to attend or at least join online, if possible.