Table 2

Classification of small ring chromosomes 1 and relationship to phenotype

Patient reference	Sex	% r(1)	De novo	Ascertainment	Phenotype
(1) 1q12 heterochromatin
Case 1, ref 10	F	25	Y	MCA	ND, del(18)(q22) also present
Case 17, refs ^{12 and} 13	M	90	ND	Adult patient with CGL	Normal
Case 1, ref 14	M	100	Y	PND	Normal
(2) 1q12 heterochromatin and euchromatin
Patient D, this report	F	15	Y	Minor dysmorphism, protruding tongue, heart murmur	Minor dysmorphism, VSD
Case 1, ref 15	F	22	Y	PND	Normal
(3) Euchromatin, 1q12 heterochromatin absent
Patient A, this report	M	30	Y	Developmental delay, minor dysmorphism	Intellectual disability, minor dysmorphism
Patient B, this report	M	30	Y	Developmental delay, diarrhoea	Intellectual disability, minor dysmorphism
Patient C, this report	M	70	Y	Language delay, dysmorphic features	Minor dysmorphism, lean build
Case 1, ref11	M	20	Y	Developmental delay, dysmorphism	Developmental delay, minor