Children with<unk>  lose developmental milestones they have previously gained. These can be motor, social, or language skills. The loss of motor skills could include loss of the ability to purposefully use hands, loss of the ability to feed oneself, loss of the ability to walk, loss of the ability to bathe oneself, and loss of the ability to dress oneself. The loss of social skills could include loss of the ability/desire to play, loss of the ability to make appropriate eye contact, and loss of interest in playing social games. The loss of language skills could include the loss of a child's ability to understand spoken speech and sounds (receptive language skills) and/or the loss of a child's ability to use words/spoken language (expressive language skills).
Developmental regression
Neuronal migration disorder
Developmental disorder
Fetal alcohol spectrum disorder
Neurodevelopmental disorder
Specific developmental disorder
Child abuse
Sexual maturation disorder