The possibility of a degenerative disorder should be considered in a hypotonic neonate with a family history of a neurodegenerative disorder, or if the neonate has a cherry red spot (Figure 112.1 [A]), hepatosplenomegaly (Figure 112.1 [B]), dysmorphic features, swollen joints, hyperplastic gums, bone dysplasia, persistent irritability, hypothermia, pili torti or evidence of white matter disease on MRI of the brain. The usual history of neurodevelopmental regression is not present during the neonatal period. Degenerative disorders that affect the newborn can be divided into those that have evidence of visceral storage and those that do not.Signs of visceral storage are hepatomegaly, cherry red spot, facial dysmorphism, hydrops fetalis, swollen joints, hypertrophic gums, and bone dysplasia.

A	B

Figure 112.1.— [A] Cherry red spot in a patient with GM1-gangliosidosis. [B] Hepatosplenomegaly in a patient with Zellweger syndrome.

Hydrops fetalis often has an inmunological origin. A degenerative disorder should be considered once inmunological causes have being eliminated.