Table 2.

Genetic abnormalities associated with dyskeratosis congenita (DC)

Gene	Chromosome	Product	Function	Mutation comments	Inheritance	% of cases
DKC1	Xq28	Dyskerin	Telomere maintenance and ribosomal biogenesis	Concentration of mutations in N-terminus. Many mutations result in exon 15 loss	XLR	Approximately 40%
TERT	5p15.33	TERT	Telomere maintenance	Located throughout gene	AD, AR	<5%
TERC	5q21–3q28	TERC	Telomere maintenance	Located throughout gene. No DC mutations in N-terminus	AD	Approximately 5%
TINF2	14q12	TIN2	Telomere maintenance	All mutations concentrated in exon 6a	AD, S	<1%
NOP10	15q14	NOP10	Telomere maintenance	Located in exon 2	AR	<1%
NHP2	22q13.2	NHP2	Ribosomal biogenesis	All mutations concentrated in exon 4	AR	<1%
TCAB1	17p13.1	TCAB1	Telomere maintenance	Located in exon 2, 7, 8, and 9	AR	<1%
C16orf57		C16orf57		Located in exon 7	AR	2%
Uncharacterizeda						40%

Note:

^aThese are likely to represent more than one genetic locus and include the genetically heterogeneous AR DC.

Abbreviations: AD, autosomal dominant; AR, autosomal recessive; S, sporadic; XLR, X-linked recessive.