The latter presents with a variable degree of growth and neurodevelopmental delay, microcephaly, thin faces with dysmorphic features, intellectual disability, language impairment, and seizures.62, 63, 64 Interestingly, persons with small 4p16.3 deletions encompassing LETM1 suggested that LETM1 might not be responsible for seizures in WHS as some individuals with LETM1 deletion did not have seizures by the age of 4 and 9 years, whereas persons with preserved WSHCR-2 including LETM1 developed seizures.64 This evidence concerns the gene LETM1 and Neurodevelopmental delay.