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Nystagmus is a rhythmical, repetitive and involuntary movement of the eyes. It is usually from side to side, but sometimes up and down or in a circular motion. It can be distressing to the child and their carers and leads to reduced visual acuity due to the excessive motion of images on the retina. It is helpful to distinguish between infantile nystagmus and acquired nystagmus. Infantile nystagmus usually appears by 3–6 months. Infantile nystagmus can occur with poor vision, or visual deprivation in early life due to congenital cataracts, optic nerve hypoplasia, retinal dystrophies or disease, can be associated to albinism or it can be part of a neurological syndromes or diseases. Neurological disease should be suspected when the nystagmus is asymmetrical or unilateral. Infantile nystagmus can be hereditary, the most common and best analysed form being a mutation of the FRMD7 gene on chromosome Xq26.2. Novel methods to record eye movements and recent advances in the field of genetics have contributed to the improvement in diagnosis and management of nystagmus in children. Glasses, contact lenses and prisms help in improving vision. Pharmacological treatment exists to reduce nystagmus; however, as there are very few randomized controlled trials in this area, most pharmacological treatment options in nystagmus remain empirical. Eye muscle surgery may help in children with abnormal head posture to correct the defect and alleviate neck problems that can arise due to an abnormal head posture. [ABSTRACT FROM AUTHOR]

Hypokalemic periodic paralysis is a genetic neuromuscular disorder characterized by episodes of painless muscle paralysis associated with low serum potassium, exclusively, during the attack. This may be precipitated by heavy exercise, fasting, or high-carbohydrate meals. We report two siblings, presenting at different ages with varying symptomatology-older sibling with episodic weakness in the morning associated with reduced physical exercise and consumption of large carbohydrate meal, whereas younger sibling complained of muscle stiffness following large carbohydrate meal and at the end of physical exercise. Molecular genetic study showed both siblings and their father were positive for calcium channel alpha-1S subunit (CACNA1S) C3716G>A; p.Arg1239His mutation. It is important to check serum potassium in a child presenting with muscle stiffness or weakness after a carbohydrate meal or vigorous exercise. This condition responds with potassium supplement. Often relevant family history and trigger factors with clinical correlation and blood results can lead to its diagnosis. [ABSTRACT FROM AUTHOR]

A young girl with l-dopa responsive dystonia showed significant improvements in motor function but had ongoing complaints of neuropsychological difficulties. A neuropsychological evaluation was undertaken to understand the nature of her difficulties. Intellectual function, attention, executive function, and academic attainment were assessed using published psychometric tests. Verbal and non-verbal reasoning was found to be age appropriate. Particular difficulties were identified with working memory, visual selective attention, dual attention, and processing speed which were having a significant impact upon the child and her family. The importance of a thorough neuropsychological evaluation is discussed in helping to appropriately manage and support the child with this chronic but rare health condition. [ABSTRACT FROM AUTHOR]

Skeletal muscle sodium channelopathies (SMSCs) including hyperkalemic periodic paralysis (HyperPP), paramyotonia congenita (PC), and sodium channel myotonia are caused by sodium channel gene (SCN4A) mutations, with altered sarcolemal excitability, and can present as episodes of skeletal muscle weakness, paralysis, and myotonia. We report a teenage boy, who presented with features of HyperPP, PC, myotonia congenita, and sodium channel myotonia. His electromyography (EMG) revealed myopathic changes, myotonia, and Fournier EMG pattern I, and posed a diagnostic challenge. Genetic analysis showed Thr704Met mutation in SCN4A gene. While with typical clinical phenotypes, the electromyographic patterns can be used to direct genetic testing, atypical phenotypes may pose diagnostic dilemmas. Clinicians dealing with neuromuscular disorders in children need to be aware of the unusual clinical presentations of SMSC, so that focused genetic testing can be carried out. [ABSTRACT FROM AUTHOR]

We detected a novel CLN1 gene mutation (p.Arg151X, heterogenous) in a 12-year-old boy. Low level of palmitoyl protein thioesterase and granular inclusion pattern in lymphocytes were also consistent with infantile Neuronal ceroid lipofuscinosis (INCL). However, the clinical phenotype was that of atypical juvenile neuronal ceroid lipofuscinosis (JNCL) and consisted of progressive visual loss from the age of 8 years. His visual acuity was 6/60 in both eyes at first presentation, 6/36 one month later, then 6/6 (right eye), and 6/60 (left eye) 6 months later. However, after 4 months, visual acuity dropped to 6/60 in both eyes and at last follow-up, it was 6/60 (right eye) and 3/60 (left eye). Visual hallucinations were also reported. Persistent normal fundi findings, normal electroretinogram (ERG), and delayed visual evoked potentials (VEP) were suggestive of non-retinal adolescence form/atypical JNCL. Visual loss in JNCL is secondary to retinal dystrophy. Our observations suggest that JNCL should be considered in any children presenting with bilateral progressive visual loss even with normal fundi and/or delayed VEP. Electron microscopy of buffy coat and palmitoyl protein thioesterase enzyme study are useful tools in diagnosis. Pertinent issues regarding clinical symptomatology, ophthalmologic findings, and laboratory results are discussed. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented which is concerned with the case of a 22 month old female patient with a rare cause of congenital ptosis: Blepharophimosis, ptosis and epicanthus inversus syndrome.

Cerebral cavernous malformations (CCMs) are vascular malformations causing seizures and cerebral hemorrhages. We report a 20-month old male with multiple CCMs associated with Krev interaction trapped 1 (KRIT1) c.845 + 1 G > C heterozygous transversion mutation. This case demonstrates the importance of molecular genetic analysis in cases of multiple CCM. [ABSTRACT FROM AUTHOR]