Table 1.

Clinical Abnormalities in TTD- or XP-Affected Individuals with ERCC2 Mutations or TTD-Affected Individuals with GTF2E2 Mutations

	TTD (ERCC2) Features	TTD379BE (GTF2E2) (c.448G>C [p.Ala150Pro])	TTD28PV (GTF2E2) (c.559G>T [p.Asp187Tyr])	XP (ERCC2) Features	Normal
repair + TRANSCRIPTION defecta	TRANSCRIPTION defect	TRANSCRIPTION defect	REPAIR + transcription defect	normal
Clinical Features
Dry skin	yes	yes	yes	yes	no
Ichthyosis	yes	yes	yes	no	no
Short, brittle hair	yes	yes	yes	no	no
Hair tiger-tail banding	yes	yes	yes	no	no
Short stature	yes	yes	yes	no	no
Microcephaly	yes	yes	yes	no	no
Developmental delay	yes	yes	yes	yes/no	no
Happy personality	yes	yes	yes	no	no
Acute burning on minimal sun exposure	yes	no	no	yes	no
Recurrent infections	yes	no	no	no	no
Increased freckle-like pigmentation	no	no	no	yes	no
Skin cancer	no	no	no	yes	no
Clinical Lab Studies
Low RBC mean corpuscular volume	yes	yes	yes	no	no
Elevated Hemoglobin A2	yes	yes	yes	no	no
Dilated brain ventricles (CT or MRI)	no	no	no	yes	no

^aTerms in all capital letters indicate greater contribution to the phenotype.