Treatment options for these severely affected infants are constantly evolving.

Most of the affected infants die early in life, and definitive diagnosis has often been made only by post-mortem evaluation.

Harlequin ichthyosis is a congenital scaling syndrome of the skin in which affected infants have epidermal hyperkeratosis and a defective permeability barrier.

Conclusions: The identification SMA affected infants via newborn screening presents an unprecedented opportunity for achievement of maximal therapeutic benefit through the administration of treatment pre-symptomatically.

Significance: These alterations may place the affected infants at a higher risk of neurological and cardiovascular complications, which could conceivably persist throughout childhood and adulthood.

Affected infants are often macrosomic, with length above the 90th centile and large head circumference.