CONTEXT: The gene for congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency, CYP21A2, is flanked by the gene encoding tenascin-X (TNXB), a connective tissue extracellular matrix protein that has been linked to both autosomal dominant and autosomal recessive Ehlers-Danlos syndrome (EDS). A contiguous deletion of CYP21A2 and TNXB has been described. OBJECTIVE: The objective of the study was to determine the frequency and clinical significance of TNXB haploinsufficiency in CAH patients. DESIGN, SETTING, AND PARTICIPANTS: A total of 192 consecutive unrelated CAH patients being seen as part of an observational study at the National Institutes of Health Clinical Center (Bethesda, MD) were prospectively studied during 2006-2010. Patients were evaluated for clinical evidence of EDS, including cardiac evaluation. DNA was analyzed by PCR, multiplex ligation-dependent probe amplification, Southern blot, and TNXB sequencing. Tenascin-X expression was evaluated by Western blot analysis of fibroblasts and immunostaining of the skin. CAH patients with TNXB haploinsufficiency were compared with age-matched CAH patients with normal TNXB (controls). Phenotyping of 7 parents with TNXB haploinsufficiency was performed. MAIN OUTCOME MEASURES: The frequency of TNXB haploinsufficiency among CAH patients and the frequency of EDS symptomatology among CAH patients with TNXB haploinsufficiency and controls. RESULTS: TNXB haploinsufficiency, here termed CAH-X syndrome, was present in 7% of CAH patients. Twelve of 91 patients carrying a CYP21A2 deletion (13%) carried a contiguous deletion that extended into TNXB. One patient carried a TNXB premature stop codon. Twelve of 13 patients with CAH-X had EDS clinical features. Patients with CAH-X were more likely than age-matched controls to have joint hypermobility (P < .001), chronic joint pain (P = .003), multiple joint dislocations (P = .004), a structural cardiac valve abnormality by echocardiography (P = .02), and reduced tenascin-X expression by Western blot and immunostaining. A subset of parents had clinical findings. CONCLUSIONS: Clinical evaluation for connective tissue dysplasia should be routinely performed in CAH patients, especially those harboring a CYP21A2 deletion.
CONTEXT: The gene for congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency, CYP21A2, is flanked by the gene encoding tenascin-X (TNXB), a connective tissue extracellular matrix protein that has been linked to both autosomal dominant and autosomal recessive Ehlers-Danlos syndrome (EDS). A contiguous deletion of CYP21A2 and TNXB has been described. OBJECTIVE: The objective of the study was to determine the frequency and clinical significance of TNXB haploinsufficiency in CAH patients. DESIGN, SETTING, AND PARTICIPANTS: A total of 192 consecutive unrelated CAH patients being seen as part of an observational study at the National Institutes of Health Clinical Center (Bethesda, MD) were prospectively studied during 2006-2010. Patients were evaluated for clinical evidence of EDS, including cardiac evaluation. DNA was analyzed by PCR, multiplex ligation-dependent probe amplification, Southern blot, and TNXB sequencing. Tenascin-X expression was evaluated by Western blot analysis of fibroblasts and immunostaining of the skin. CAH patients with TNXB haploinsufficiency were compared with age-matched CAH patients with normal TNXB (controls). Phenotyping of 7 parents with TNXB haploinsufficiency was performed. MAIN OUTCOME MEASURES: The frequency of TNXB haploinsufficiency among CAH patients and the frequency of EDS symptomatology among CAH patients with TNXB haploinsufficiency and controls. RESULTS:TNXB haploinsufficiency, here termed CAH-X syndrome, was present in 7% of CAH patients. Twelve of 91 patients carrying a CYP21A2 deletion (13%) carried a contiguous deletion that extended into TNXB. One patient carried a TNXB premature stop codon. Twelve of 13 patients with CAH-X had EDS clinical features. Patients with CAH-X were more likely than age-matched controls to have joint hypermobility (P < .001), chronic joint pain (P = .003), multiple joint dislocations (P = .004), a structural cardiac valve abnormality by echocardiography (P = .02), and reduced tenascin-X expression by Western blot and immunostaining. A subset of parents had clinical findings. CONCLUSIONS: Clinical evaluation for connective tissue dysplasia should be routinely performed in CAH patients, especially those harboring a CYP21A2 deletion.
Authors: N C Voermans; G J Jenniskens; B C Hamel; J Schalkwijk; P Guicheney; B G van Engelen Journal: Am J Med Genet A Date: 2007-09-15 Impact factor: 2.802
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Authors: B L Therrell; S A Berenbaum; V Manter-Kapanke; J Simmank; K Korman; L Prentice; J Gonzalez; S Gunn Journal: Pediatrics Date: 1998-04 Impact factor: 7.124
Authors: David F Egging; Ivonne van Vlijmen-Willems; Jiwon Choi; Anita C T M Peeters; Desiree van Rens; Guido Veit; Manuel Koch; Elaine C Davis; Joost Schalkwijk Journal: Cell Tissue Res Date: 2008-03-12 Impact factor: 5.249