There were 21 subjects in this study, with mean age of 15,87 years old for classical Turner syndrome group (SD = 2,53) and 18,15 years old for mosaic Turner syndrome group (SD = 3,10). Turner syndrome diagnosis was made on various ages, and mostly the diagnosis was made during adolescence (age group >12–18 years old). Only 1 out of 21 cases (4,8%) was diagnosed at birth. Some possible USG imaging which might be seen during gestation suggestive of Turner syndrome diagnosis are increased nuchal translucency, cystic hygroma, and left heart obstruction anomaly (especially coarctation aorta) . Age of diagnosis in this study was different from a study by Savendahl and Davenport which stated that Turner syndrome diagnosis was made at birth (15%), adolescence (26%), and adulthood (38%) . Delay in diagnosis will have an impact on the intervention. As the result, the therapy will likely be delayed.
The mean father’s/mother’s age at conception for both karyotypes was below 35 years and there was no significant difference between classical and mosaic groups (p > 0.05). This finding matched the literature which mentioned that Turner syndrome prevalence was not affected by mother’s and father’s age at conception [1, 2]. There was no significant difference in the mean of birth weight and length between both karyotypes (p > 0.05). In this study, birth weight mean in classical karyotype was 2,720 gram (SD = 240) and in mosaic karyotype was 2.750 gram (SD = 230). In this research, birth length mean on classical karyotype and mosaic karyotype was 47,1 cm (SD = 1.46) and 47,2 cm (SD = 1.64), respectively. Delayed development characteristic in Turner syndrome happened since intrauterine phase and continued during childhood, followed by growth spurt failure that happened during puberty [4, 5, 7].
Karyotype distribution in this research consisted of 62% mosaic karyotype and 38% classical karyotype. Previous study prevalence stated that about 50% of Turner syndrome consisted of 45 XO karyotype, 25% were having partial X chromosome deletion, and 20% were having mosaic karyotype with variety, especially 45 XO/46XX, and a small number of Turner syndrome patients carried XY gene [2, 11].
In this research, the mean age of the start of estrogen hormone therapy was 14,3 (SD = 1,9) years old in mosaic group and 14,0 (SD = 0.8) in classical group. There was a difference compared to the guideline which was mentioned earlier. Since most of the diagnosis in this study was made on puberty, the estrogen hormone therapy could not be started earlier. Based on the recommendation from Cincinnati International Turner Syndrome Meeting on 2016, fertility therapy had to be offered since young age. Oocytes preservation can be done after the patient’s age reaches 12 years. Mosaic Turner syndrome patients at a young age with persistent ovary function can be counseled to preserve their fertility by doing oocyte cryopreservation . In this study, every subject went through further examination with obstetrics–gynecologist endocrine consultant to examine whether there was a possibility of doing fertility preservation.
There are some differences in the protocols of starting estrogen hormone therapy in several countries. In the Royal Children’s Hospital in Australia, estrogen hormone therapy is started at 13–14 years old if there are no spontaneous signs of puberty after growth hormone therapy has been given before. The purpose of this therapy is for the secondary sexual characteristics development to catch up to the patient’s age, synergistically with the growth hormone effect. Natural estradiol on low dose is increased step by step for 2,5–3 years, by adding cyclic progesterone at the end of period. Estrogen hormone therapy will be delayed if possible until 13–14 years to allow growth catchup with growth hormone therapy . At Sophia Children’s Hospital in Netherlands, puberty induction protocol is started at 12 years old, 2 years after normal puberty age in Netherland children. Induction is started by giving natural estrogen 17b-estradiol at a very low dose for 2 years, and the dose is slowly increased. Natural estrogen is chosen for this therapy, since natural estrogen does not have any effect on coagulation factor, lipid profile, and blood pressure compared to synthetic estrogen .
Significant correlation was found between karyotype and Tanner puberty stage M (mammae) (p = 0.035). Mosaic karyotype group showed better breasts growth and development compared to the classical karyotype group. This finding matched a study done by Wu and Li on 124 classical and mosaic Turner syndrome patients who came to pediatric polyclinic at the Capital Institute of Beijing. Secondary sexual characteristic growths were found to be better in mosaic karyotype . Estrogen hormone plays an important role in breasts development. Low dose of estrogen hormone therapy, when given at appropriate age for children with Turner syndrome, will be helpful to make the breasts grow normally although the normal growth of breasts will be reached at the age 2 years later compared to normal girls . In this study, pubic hair puberty stage (P stage) did not have a significant difference between classical and mosaic karyotypes. This result was similar with a study done by Bannink et al. at 56 children with Turner syndrome prospectively. Pubic hair growth in Turner syndrome patient was the same with normal women, although it was a bit late. In Turner syndrome, androgen hormone disturbance only happened in the ovary while androgen hormone remains normal at the adrenal gland; thus, the adrenarche/pubarche in Turner syndrome is the same with normal women .
No significant correlation was found between karyotype and mean uterine (p = 0.426) and right and left ovary (p = 0.586; p = 0.663) volumes. This result was the same with a cross-sectional study done by Elsedfy et al. at Kairo on 40 Turner syndrome patients aged 9,71–26,32 years old using transabdominal USG. The result was the size of uterine was not affected by karyotype (p = 0.40). Elsedfy et al. also analyzed the correlation between uterine size and the type of therapy, and no significant correlation was found . This result did not match a cross-sectional study done by Haber and Ranke, using transabdominal USG in 93 Turner syndrome patients aged 12 days until 17,85 years with 190 normal, healthy girls as control group, which stated that there was a significant correlation between karyotype and size and volume of uterus in Turner syndrome patients. The mean of uterine length and volume in patients with 45XO karyotype was smaller than the variant karyotype . A research done by Liang et al. in 51 children with Turner syndrome compared to 20 healthy girls also stated that the sizes of uterus in children with 45XO karyotype in Turner syndrome were smaller compared to other types besides 45XO (p < 0.05) . A prospective USG study for 3 years in the Royal Children’s Hospital in Australia by Donnel et al. on 18 girls with Turner syndrome who had got estrogen and growth hormone therapy during infancy and adolescent years showed that normal uterine size can be reached when the exact amount of estrogen in the body can be maintained during puberty .
This was the first study in the world which was done using transrectal USG to examine the development of uterus and ovary in adolescents with Turner syndrome while evaluating its correlation with karyotype. Several studies which had been done previously only used transabdominal USG. In this study, the USG examination was done by an experienced obstetrics–gynecology endocrine fertility consultant. USG is a widely available diagnostic tool which is used to examine internal genital condition including the uterus, ovary, and adnexa. Routes of examination in USG include transvaginal, transabdominal, and transrectal. Transvaginal USG has several benefits compared to transabdominal, such as a clearer image production, the target organ can be located at focal distance, and the probe can be put within the reach of target organ area. However, there are several limitations too when using transvaginal USG, such as it cannot be done when there is vaginal agenesis, it cannot be done on women with intact hymen (on virgins), and it also cannot be done when there is a possibility of infection. Transrectal USG is as effective as transvaginal USG to obtain internal genitalia structure, with its probe still located within the reach of target organ area [12, 20].
In this study, there were two subjects with classical karyotype, whose uterus and ovaries were hard to identify when transrectal USG was done. Mullerian dysgenesis was suspected in these patients. This condition was similar with the finding in a study done by Haber and Ranke, which stated that only 41 (44%) out of 93 Turner syndrome patients’ ovaries can be visualized. In Turner syndrome patients, the shapes of the ovary vary a lot, including streak which contains fibrous tissue and gonad with normal shape and function . In this study, bilateral gonadectomy was done at two mosaic karyotype subjects with Y chromosome as a preventive measure for malignancy. Although gonadectomy had been done, we did not exclude the subjects in the analysis to see more of the ovary shape variations in Turner syndrome patients. Gonadoblastoma might happen during infancy. Thus, it was advised for a Turner syndrome patient who carries Y chromosome material at FISH test to do prophylactic gonadectomy [5, 7]. A similar situation was found in a study done by Donnel et al., which stated that 3 out of 18 patients with Turner syndrome with Y chromosome had bilateral gonadectomy . A linear regression analysis done by examining the role of karyotype on the shape and volume of the uterine and the right and left ovary volume on the patients who underwent estrogen hormone therapy on certain duration showed no significant correlation (p > 0.05). This finding is similar with the result of the research done by Elsedfy et al. in 40 patients with Turner syndrome, which stated that karyotype did not affect the size of the uterus (p = 0.40) .
The strength of this study is that this is the first study in Indonesia which determines the correlation between karyotype and puberty stage and uterine volume and ovary using transrectal USG in adolescents with Turner syndrome.
The limitation of this study is the difficulty in collecting the subjects, since Turner syndrome is a rare disease that only happens in women. Several parents of the children with Turner syndrome did not allow their children to join this study because they feel ashamed if other people find out about their children’s disease. Since July to December 2018, only 21 patients could join this study, recruited from many areas including Jakarta, Bogor, Depok, Tangerang, Bekasi, West Jawa, and Lampung.