An unusual development of Salla disease in a SallaFIN patient; A research highlight.

The patient’s birth was uneventful and she was not diagnosed until three years of age due to clinical symptoms and a heightened level of sialic acid in urine. For the first year of life, her development was normal except for struggling with stable crawling and muscle hypotonia as well as nystagmus that appeared to have resolved as she grew up. She spoke her first word by age 1 and her first sentence by 2. At 1 year and 6 months, she learned how to walk although her balance and gait appeared to be abnormal. Furthermore, at 3 years of age,f she appeared to have normal cognitive development aside from some mild delays in motor tasks, eye-hand coordination and concentration, as well as verbal development and dyspraxia. By the time she was 6, it was assessed that her developmental delay was about 2 years. During her childhood, the proband (the studied patient) appeared to have struggled with inattentiveness, hyperactivity, and problems with sleep, balance and body awareness. Additionally, she experienced some ataxic symptoms that seem to have diminished when moving onto teenage years.Throughout her school years, her neurocognitive development varied greatly; verbal performance was consistently surpassing her visual performance and fine motor skills. The overall intellectual disability was classified as mild. According to the Wechsler Intelligence Scale for Children-R test, at 12 years of age, she had the verbal skills of a 7-year-old, performance abilities between 5 years 6 months and 6 years 6 months. When tested again at 14 years of age, the neurocognitive state was stable and her verbal skills continued to surpass her motor and visual skills, and it was determined that her developmental age was 4-8 years old.

The proband regularly engaged in physical activities, had a social life, was not taking any medication, and was able to live independently with assistance. When the neurological examination was performed, the ECG showed normal cardiac results, her muscle strength, skin sensation, and symmetrical tendon reflexes all seemed normal. However, her facial features appeared to be slightly coarse, and although she could walk without aid, her feet remained in a pes planus (flat foot) position. Furthermore, while walking, she displayed athetotic movements in her upper extremities, and both Achilles tendons were slightly shortened in addition to the mild spasticity in the legs. Additionally, when Romberg’s test was performed the proband seemed slightly unstable and could not stand with her eyes closed. Eye movement was normal, although there was marked myopia and outward strabismus detected in her right eye.

The proband’s neurological condition and motor skills had not deteriorated in 10 years but have improved aside from the slowing speed of her motor actions. When an EEG was performed at 3 years of age, there was some mild generalized background abnormality of concern, however, when repeated at 15 years of age, it came back normal and there was no history of epileptic seizures.

The proband regularly engaged in physical activities, had a social life, was not taking any medication, and was able to live independently with assistance. When the neurological examination was performed, the ECG showed normal cardiac results, her muscle strength, skin sensation, and symmetrical tendon reflexes all seemed normal. However, her facial features appeared to be slightly coarse, and although she could walk without aid, her feet remained in a pes planus (flat foot) position. Furthermore, while walking, she displayed athetotic movements in her upper extremities, and both Achilles tendons were slightly shortened in addition to the mild spasticity in the legs. Additionally, when Romberg’s test was performed the proband seemed slightly unstable and could not stand with her eyes closed. Eye movement was normal, although there was marked myopia and outward strabismus detected in her right eye.

The proband’s neurological condition and motor skills had not deteriorated in 10 years but have improved aside from the slowing speed of her motor actions. When an EEG was performed at 3 years of age, there was some mild generalized background abnormality of concern, however, when repeated at 15 years of age, it came back normal and there was no history of epileptic seizures.

The Wechsler Intelligence Scale for Children-III was used to estimate the proband’s developmental state at 30 years of age to be that of 7 years and 9 months on the verbal scale, and 5 years and 4 months on the perceptual scale. While some skills have improved, others have diminished or gotten delayed. Her neurocognitive results were markedly higher than those of the other patients as the Wechsler children’s tests were too challenging for them. Her visual skills have enhanced and she was able to learn and repeat long, logical stories and was able to test well for basic functional mobility although there was some verbal and oral dyspraxia. Additionally, there was some delay in her visuomotor speed, eye-hand coordination, visual reasoning and spatial orientation, as well as diminished visuoconstructive skills.

Although some motor difficulties were present, such as an unsteady forward tandem walk and unstable motor persistence and coordination, the overall symptoms had not progressed when a follow-up was done. She tested and performed slowly but correctly in Static and dynamic cerebellar tests.

At the age of 15, brain imaging was carried out ,revealing dysmyelination and a hypoblastic corpus callosum, however, all other parts of the brain appeared completely normal. An MRI was performed at 30 years of age presenting mild findings.

The case discusses a patient with an unusual developmental profile of SD in comparison to other conventional subtype SD patients. Her condition and development remained consistent with only slight progression in the symptoms regarding her neurocognitive skills. Aside from her interest in physical activity, she regularly attended physiotherapy, all of which benefited her in multiple areas including her brain, the health of her neural network, as well as her ability to process information. It is important to note that the unknown genetic and environmental factors may play a role in this unique SD type.