Background: Shox gene, located on the short arm (p) of the X chromosome, is expressed in the growth plate cartilage in pre and post natal life. Whereas the dose dependent association between the number of active copies of the SHOX gene and height is well established, studies addressing a more subtle variability between the quality of fetal growth, the severity of post natal height deficit and karyotype subgroups in Turner syndrome (TS) are still limited.
Objective: The aim of this large observational cohort study was to examine whether fetal and post natal growth in TS were associated with the karyotype subgroups.
Method: Birth weight and length, expressed as SDS for gestational age, and height minus target height (TH) SDS before GH treatment, were analyzed according to karyotype in a national cohort of 1532 patients with TS.
Results: Unless in patients with caryotype including ring X, BW were less affected than BL in all subgroups. The degree of fetal growth retardation and the post natal height deficit in untreated GH patients were associated with the karyotype subgroups, with patients with structural abnormalities of the X chromosome (isoXq which includes deletion of the short and duplication of the long arms, and ring X formation) or monosomy X more severely affected than patients with mosaicism or with the Y chromosome.
|XrX||Iso (Xq)||45X0||45X/46XX||Presence of Y||Others|
|Birth weight SDS||−1.56±1.33||−1.22±1.20||−0.96±1.13||−0.73±1.31||−0.68±1.21||−0.89±1.21|
|Birth length SDS||−1.52±1.12||−1.31±1.18||−1.21±1.06||−0.85±1.23||−0.99±1.04||−1.08±1.11|
|Height -TH SDS||−2.7±1.1||−2.8±1.1||−2.4±1.1||−2.1±1.0||−2.2±1.2||−1.9±1.3|
|Chronological age (years)||8.0±4.2||9.1±4.1||8.1±4.3||9.4±3.9||8.7±3.4||9.1±3.8|
Conclusion: In TS, the deficit of fetal and post natal growth is related to karyotype.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology