Affected children are usually very floppy at birth and have major feeding problems requiring tube feeding. They have generally decreased movements, particularly facial movements. Some, but not all, children have heart problems and some have an absent midline structure of the brain (absent corpus callosum; see entry Agenesis of the Corpus Callosum). When the teeth erupt they are often very small. Many older children have joint problems ranging from mild bending of the fingers to more severe hip disorders and problems with dislocation of the kneecap.
Progress in the first year of life is slow, and head control, sitting and walking occur late but ultimately, progress is often better than was anticipated at first. All children have mild-to-moderate learning difficulties (see entry Learning Disability). Thyroid problems (underactive or overactive) appear to occur with an increased incidence in Ohdo syndrome (see entry Thyroid disorders).