Table 1.
Variant Type | Variant (Protein) | Variant (DNA) | Splicing Effect | ExAC DB Frequency | PP2 | Affected Carrier Telomere % | Segregates with Disease |
---|---|---|---|---|---|---|---|
Loss of function variants | |||||||
Frameshift | p.Thr296SerfsX14 | c.887_888delCA | NA | None | NA | 2%, 3% | Yes |
Splice | NA | c.620+5G>A | Yes | None | NA | 1% | Yes |
Nonsense | Glu189Stop | c.565G>T | NA | None | NA | 1%, 1%, 12% | Yes |
Frameshift | p.Phe418PhefsX6 | c.1251delT | NA | None | NA | 15% | No* |
Variants of uncertain significance | |||||||
Missense | Asn7His | c.19A>C | Unknown | None | 1 | 3% | Yes |
Missense | Lys56Asn | c.168G>C | NA | G=1/C=66,604 | 0.667 | 5%, 5% | Yes |
Intron | NA | c.178-3C>T | No | None | NA | 7%, 9% | Yes |
Intron | NA | c.703-11_703-10delAT | Unknown | None | NA | 1%, 2% | Yes |
Intron | NA | c.245+75_245+77delCCC | Unknown | NA | NA | 15% | No* |
Synonymous | Ala153Ala | c.459G>C | Unknown | None | NA | 21%, 22% | No† |
Intron | NA | c.840+6T>C | Unknown | G=33/A=66,636 | NA | 1% | No‡ |
Intron | NA | c.1006-11G>A | Unknown | G=3/A=65,604 | NA | 1%, 2% | Yes¶ |
Missense | Ser498Asn | c.1493G>A | NA | G=20/A=60,728 | 0.996 | 1% | No |
Definition of abbreviations: ExAC DB = Exome Aggregation Consortium database; NA = not applicable; PARN = polyadenylation-specific RNase deadenylation nuclease; PP2 = PolyPhen2; TERT = telomerase reverse transcriptase.
p.Phe418PhefsX6 was not detected in one affected participant; however, this subject carried an intronic variant of uncertain significance, c.245+75_245+77delCCC.
One subject did not carry c.459G but had a family history of idiopathic pulmonary fibrosis in both parental lines.
Two subjects did not carry c.840+6T>C; however, they had a family history of idiopathic pulmonary fibrosis in both parental lineages.
This family also has a novel segregating TERT variant Thr839Lys.