A case of 46,XX dysgenesis and marked tall stature; the need for caution in interpreting array comparative genomic hybridization (CGH).
BACKGROUND
Gonadal dysgenesis with an apparently normal 46,XX karyotype is a rare cause of hypergonadotrophic hypogonadism. Tall stature is not a widely recognized association.


METHODS
A 15-year-old girl presented with primary amenorrhoea. Examination showed a non-dysmorphic girl of normal intellect with no breast development (Tanner stage B1P4A1) who was tall compared with her parents: height standard deviation score (SDS) +1.56 vs. midparental height of +0.23 SDS, and slim build (weight -0.13 SDS). Investigations showed a 46,XX karyotype, elevated gonadotropins (FSH 119 and LH 33.7 IU/L), serum estradiol <5 pmol/L, uterine length 3.75 cm with cylindrical shape, and absent ovaries on ultrasound. Initially, a 364055-bp deletion on Xp21.2 was reported on array CGH. However, repeat analysis using BlueGnome CytoChip ISCA 4x180k v2.0 array was normal. With oral ethinyl estradiol induction puberty progressed to B4P4A2 but aged 18.4 years, the patient was remarkably tall with height SDS +2.88, weight SDS +0.97.


CONCLUSIONS
Caution is needed in interpreting small changes with array CGH, particularly with the older assays. We postulate that the genetic change causing 46,XX gonadal dysgenesis in our patient may have also resulted in unsuppressed somatic growth. More critical height assessment, including parental height measurement, of future patients with 46,XX gonadal dysgenesis is recommended in order to determine whether or not a true association with tall stature may be present in certain cases.
Vidya Kanamkote
VK
Narayanan
Mira
M
Kharbanda
Malcolm
M
Donaldson
D000293:Adolescent; D001827:Body Height / Q000235:genetics*; D055028:Comparative Genomic Hybridization / Q000379:methods*; D005260:Female; D006059:Gonadal Dysgenesis / Q000503:physiopathology*; D006801:Humans; D011379:Prognosis