Table 1

Characteristics of presentation in children with hypocalcaemia secondary to malignant infantile osteopetrosis

UPN	Age when hypocalcaemic (days)	Initial symptoms	Age at diagnosis (days)	Additional features at diagnosis
1	1	Focal convulsion	1
2		4		Focal fitting	10
				Snuffling
3B	5	Generalised convulsion	2
3A		<14		Severe jittering during first 2 weeks		60		Macrocephaly
								Visual failure
								Hepatosplenomegaly
4		8		Poor feeding	76		Visual failure
				Twitching			Anaemia
				Brief “spasms”			Macrocephaly
							Snuffling
5B		10		Jaundice	30
				Vomiting
				Snuffling
6		14		Generalised convulsions		210		Visual failure
								Anaemia
								Hepatosplenomegaly
								Macrocephaly
								Snuffling
5A		43		Snuffling	43
				Generalised convulsions

When there were two affected children within a family, these are denoted A or B according to their order of birth. Child 3B was diagnosed by routine x ray examination on day 2 because of the previous family history.
UPN, unique patient number.