In the younger sister with the classical phenotype, feeding difficulties with recurrent gastro-oesophageal reflux prompted us to treat her temporarily with high-dose serine (1400 mg/kg/day). [ncbi.nlm.nih.gov]

In addition, the patients were irritable, hypertonic, had feeding difficulties and appeared to be “unhappy” infants. EEG recordings showed several seizure types, including hypsarithmia and multifocal epileptic activity (de Koning et al. 2002 ). [link.springer.com]

In addition, he had generalised hyperlaxity of large and small joints and striae rubra on his abdomen and upper legs. His cranial MRI revealed no abnormalities. [link.springer.com]

Finally, a severe spastic quadriplegia becomes evident during the first years of life. In addition, the patients were irritable, hypertonic, had feeding difficulties and appeared to be “unhappy” infants. [link.springer.com]

He visits a secondary school for children with learning difficulties and is actively involved in sports. At the time of diagnosis he was 16 years old and demonstrated hyperactive behaviour and mild developmental delay with an IQ of 49. [link.springer.com]

His neurological exam was unremarkable except for a subtle bilateral ankle clonus. In addition, he had generalised hyperlaxity of large and small joints and striae rubra on his abdomen and upper legs. His cranial MRI revealed no abnormalities. [link.springer.com]

At the time of diagnosis he was 16 years old and demonstrated hyperactive behaviour and mild developmental delay with an IQ of 49. His head circumference was 55 cm (10th centile) whereas his height and weight were both at the 75th centile. [link.springer.com]

Finally, a severe spastic quadriplegia becomes evident during the first years of life. In addition, the patients were irritable, hypertonic, had feeding difficulties and appeared to be “unhappy” infants. [link.springer.com]

EEG recordings showed several seizure types, including hypsarithmia and multifocal epileptic activity (de Koning et al. 2002 ). Cranial MRI scans showed a striking absence of white matter volume and hypomyelination (de Koning et al. 2000 ). [link.springer.com]

At the age of nine years he presented with absence seizures (complex typical absences) and his EEG recording showed bilateral synchronous spike-wave complexes, which were enhanced after hyperventilation with typical 3 Hz spike wave complexes. [link.springer.com]