Growth and nutrition in children with trichothiodystrophy.

OBJECTIVES: Trichothiodystrophy (TTD) is a rare autosomal recessive disorder of DNA repair and transcription. Patients have multisystem abnormalities, including alterations in growth and development. This report characterizes the growth and nutritional status of a cohort of children with TTD. METHODS: Twenty-five patients with TTD were evaluated through a natural history study of patients with DNA repair diseases at the National Institutes of Health. Mean length of follow-up was 2.7 years. Retrospective and prospective data on nutritional status and height/weight were collected. RESULTS: In general, patients with TTD had considerable abnormalities in growth, with a mean height-for-age z score of -2.75 and a mean weight-for-age z score of -2.60 at baseline clinical evaluation. The median weight-for-length at baseline was, however, 50th percentile and indicators of adequate nutrition such as serum albumin, hemoglobin, and vitamins D and B12 were largely within normal limits. Changes in growth parameters as children aged were characterized by further separation from standard growth curves (change height-for-age z score/year [-0.18 ± 0.42] and weight-for-age z score/year [-0.36 ± 0.51]). Patients who died during follow-up (n = 5) had significantly lower standardized height (P = 0.03) and weight (P = 0.006), weight-for-length (<0.0001), and higher heart rates (P = 0.02) compared with the remainder of the cohort. CONCLUSIONS: Children with TTD have markedly diminished weight-for-age and height-for-age relative to reference populations. The cause for this stunted growth remains unclear but does not appear to be related to poor nutrient absorption or malnutrition.

Accelerated aging pathology in ad libitum fed Xpd(TTD) mice is accompanied by features suggestive of caloric restriction.

Trichothiodystrophy (TTD) patients with a mutation in the XPD gene of nucleotide excision repair (NER) have a short life span and show various features of premature aging, thereby linking DNA damage to the aging process. Xpd(TTD) mutant mice share many features with TTD patients, including a shorter life span, accompanied by a segmental progeroid phenotype. Here we report new pathology features supportive to the premature aging phenotype of Xpd(TTD) mice. Strikingly, accelerated aging pathology is accompanied by signs suggestive of caloric restriction (CR), a condition usually linked to retardation of age-related pathology and life extension. Accelerated aging symptoms in Xpd(TTD) mice are most likely due to accumulation of endogenously generated DNA damage and compromised transcription leading to cell death, whereas CR symptoms may reflect the need of Xpd(TTD) mice to reduce metabolism (ROS production) in an attempt to extend their life span. Our current findings in Xpd(TTD) mice further strengthen the link between DNA damage, repair and aging.