GH successful treatment in a female with a de novo 46,XX,add(X)(p36),t(X;Y)(p36.3;p11.2), growth impairment and SHOX-haploinsufficiency

Abstract

Children with chromosome translocations, concerning X chromosome, have a genetic pattern different from Turner syndrome; however, when a translocation involves the of part of X chromosome including short stature homeobox-containing Sex-determining Region Y gene, growth may be severely compromised.We describe the clinical case of a 2.2-year-old-female, arrived at our paediatric unit for a decrease of height velocity. The karyotype was 46,XX,add(X)(p36.3). Array comparative genomic hybridization showed a fragment of Y chromosome, extended from 8.803.981 (Yp11.2) to 28.767.604 (Yq11.23). The final karyotype was 46,XX,add(X)(p36),t(X;Y)(p36.3;p11.2). Fluorescence in situ Hybridization analysis using Sex-determining Region Y probe revealed no signal on the derivative Y chromosome.At the admittance, height was 84.5 cm (- 1.24 SDS); SPAN was 79 cm; sitting height: 72.4 cm; weight was 17.5 kg. Bone age was 1.2 years. Multiplex Ligation Probe Amplification showed a heterozygous deletion of the Short Stature Homeobox-containing gene and of the pseudoautosomal region-1. This result correlated with Leri-Weill Syndrome. She started Growth Hormone treatment, with a good response.The case described shows a rare translocation, involving the X chromosome and including SHOX gene and the pseudoautosomal region-1. At our knowledge, this is the first case of a patient with a karyotype 46,XX,add(X)(p36),t(X;Y)(p36.3;p11.2) and Short Stature Homeobox-containing gene haploinsufficiency, successfully treated with Growth Hormone.

Keywords: Chromosome translocation; Growth hormone; SHOX haploinsufficiency; Treatment adherence.