X-chromosome gene dosage as a determinant of impaired pre and postnatal growth and adult height in Turner syndrome

International audienceOBJECTIVE:Short stature is a key aspect of the phenotype of patients with Turner syndrome (TS). SHOX haploinsufficiency is responsible for about two-thirds of the height deficit. The aim was to investigate the effect of X-chromosome gene dosage on anthropometric parameters at birth, spontaneous height, and adult height (AH) after growth hormone (GH) treatment.DESIGN:We conducted a national observational multicenter study.METHODS:Birth parameter SDS for gestational age, height, and AH before and after GH treatment respectively, and height deficit with respect to target height (SDS) were classified by karyotype subgroup in a cohort of 1501 patients with TS: 45,X (36%), isoXq (19%), 45,X/46,XX (15%), XrX (7%), presence of Y (6%), or other karyotypes (17%).RESULTS:Birth weight, length (P<0.0001), and head circumference (P<0.001), height and height deficit with respect to target height (SDS) before GH treatment, at a median age of 8.8 (5.3-11.8) years and after adjustment for age and correction for multiple testing (P<0.0001), and AH deficit with respect to target height at a median age of 19.3 (18.0-21.8) years and with additional adjustment for dose and duration of GH treatment (P=0.006), were significantly associated with karyotype subgroup. Growth retardation tended to be more severe in patients with XrX, isoXq, and, to a lesser extent, 45,X karyotypes than in patients with 45,X/46,XX karyotypes or a Y chromosome.CONCLUSION:These data suggest that haploinsufficiency for an unknown Xp gene increases the risk of fetal and postnatal growth deficit and short AH with respect to target height after GH therapy

SRY ‐negative 46,XX testicular/ovotesticular DSD: Long‐term outcomes and early blockade of gonadotropic axis

International audienceObjective: SRY-negative 46,XX testicular and ovotesticular disorders/differences of sex development (T/OTDSD) represent a very rare and unique DSD condition where testicular tissue develops in the absence of a Y chromosome. To date, very few studies have described the phenotype, clinical and surgical management and long-term outcomes of these patients. Particularly, early blockade of the gonadotropic axis in patients raised in the female gender to minimize postnatal androgenization has never been reported.Design: Retrospective description of sixteen 46,XX T/OTDSD patients.Results: Sixteen 46,XX SRY-negative T/OTDSD were included. Most (12/16) were diagnosed in the neonatal period. Sex of rearing was male for six patients and female for ten, while the clinical presentation varied, with an external masculinization score from 1 to 10. Five patients raised as girl were successfully treated with GnRH analog to avoid virilization during minipuberty. Ovotestes/testes were found bilaterally for 54% of the patients and unilaterally for the others (with a contralateral ovary). Gonadal surgery preserved appropriate tissue in the majority of cases. Spontaneous puberty occurred in two girls and one boy, while two boys required hormonal induction of puberty. One of the girls conceived spontaneously and had an uneventful pregnancy. DNA analyses (SNP-array, next-generation sequencing and whole-exome sequencing) were performed. A heterozygous frameshit mutation in the NR2F2 gene was identified in one patient.Conclusions: This study presents a population of patients with 46,XX SRY-negative T/OTDSD. Early blockade of gonadotropic axis appears efficient to reduce and avoid further androgenization in patients raised as girls

Turner syndrome: French National Diagnosis and Care Protocol (NDCP; National Diagnosis and Care Protocol)

International audienceTurner syndrome (TS; ORPHA 881) is a rare condition in which all or part of one X chromosome is absent from some or all cells. It affects approximately one in every 1/2500 liveborn girls. The most frequently observed karyotypes are 45,X (40-50%) and the 45,X/46,XX mosaic karyotype (15-25%). Karyotypes with an X isochromosome (45,X/46,isoXq or 45,X/46,isoXp), a Y chromosome, X ring chromosome or deletions of the X chromosome are less frequent. The objective of the French National Diagnosis and Care Protocol (PNDS; Protocole National de Diagnostic et de Soins) is to provide health professionals with information about the optimal management and care for patients, based on a critical literature review and multidisciplinary expert consensus. The PNDS, written by members of the French National Reference Center for Rare Growth and Developmental Endocrine disorders, is available from the French Health Authority website. Turner Syndrome is associated with several phenotypic conditions and a higher risk of comorbidity. The most frequently reported features are growth retardation with short adult stature and gonadal dysgenesis. TS may be associated with various congenital (heart and kidney) or acquired diseases (autoimmune thyroid disease, celia

X chromosome gene dosage as a determinant of congenital malformations and of age-related comorbidity risk in patients with Turner syndrome, from childhood to early adulthood

International audienceObjective Turner Syndrome is associated with several phenotypic conditions associated with a higher risk of subsequent comorbidity. We aimed to evaluate the prevalence of congenital malformations and the occurrence of age-related comorbid conditions and to determine whether the frequencies of congenital and acquired conditions depend on X chromosome gene dosage, as a function of karyotype subgroup. Design and methods This national retrospective observational cohort study includes 1501 patients. We evaluated the prevalence of congenital malformations and the cumulative incidence of subsequent specific comorbidities at five-year intervals, from the ages of 10 to 30 years, with stratification by karyotype subgroup: 45,X (n = 549), 45,X/46,isoXq (n = 280), 46,X,r(X)/46,XX (n = 106), 45,X/46,XX (n = 221), presence of Y (n = 87). Results Median age was 9.4 (3.7-13.7) years at first evaluation and 16.8 (11.2-21.4) years at last evaluation. Congenital heart (18.9%) malformations were more frequent in 45,X patients, and congenital renal (17.2%) malformations were more frequent in 45,X, 45,X/46,isoXq and 46,X,r(X)/46,XX patients than in those with 45,X/46,XX mosaicism or a Y chromosome (P < 0.0001). The cumulative incidence of subsequent acquired conditions, such as thyroid disease, hearing loss, overweight/obesity, dyslipidemia and, to a lesser extent, celiac disease, glucose intolerance/type 2 diabetes, hypertension and liver dysfunction increased with age, but less markedly for patients with mosaicism than for those with other karyotypes. Patients with a ring chromosome were more prone to metabolic disorders. Conclusion These data suggest that X gene chromosome dosage, particularly for Xp genes, contributes to the risk of developing comorbidities