A 10.3-year-old girl presented to the Children’s Walk-in Endocrinology Center (CWEC) in Bushehr, located on the northern shore of the Persian Gulf, accompanied by her parents, with the chief complaint of short stature and failure to thrive. She was the first child of Persian non-consanguineous parents from southern Iran. Her father was an engineer and her mother was a teacher. The family was of high socioeconomic and normal psychosocial status. The second child of the family was a 4.5-year-old girl with normal growth and development who had not required any specific medical attention. The patient was the product of a normal vaginal delivery at a gestational age of 32 weeks, with a birth weight of 2400 g. Her birth length and head circumference were 41 and 30 cm, respectively. She was conceived when her mother was 26 and her father 32 years old. According to our patient's infantile weight and height growth chart, she was in the third percentile in the first 4 months, and continued to ascend in the third percentile for age and sex with normal height velocity up to the age of 2 years. Sufficient information about her growth velocity was not available beyond that age. She had been examined intermittently by endocrinologists between the ages of 4 and 9 years due to failure to thrive and short stature. Three provocative growth hormone (GH) tests were performed during that time. The first was conducted with levodopa provocation when she was 4.9 years old. The second and third tests were carried out with clonidine provocation (5 mcg/kg) when she was 7.8 and 9.1 years old, respectively. The results of GH provocation tests were 5.11 ng/mL (at the age of 4.9 years), 10.5 ng/mL (at the age of 7.8 years), and 6.99 ng/mL (at the age of 9.1 years). Two of the tests showed no response, and therefore GH replacement therapy [somatropin, NordiLet pen 5 mg/1.5 mL (35 mcg/kg/day)] was initiated and delivered via subcutaneous injections, nightly, six times per week. Eight months later, the treatment was ceased because the patient had not gained acceptable growth velocity and height. In addition to the above treatment, she was on oral supplements including zinc 5 mg daily and multivitamins, but her parents were not aware of the exact dosage and type of vitamins. Other pathologies which were initially checked in this case were thyroid function tests, screening for celiac disease, and kidney and liver function tests, which were all at normal levels. Plain X-ray of her left hand and wrist did not detect any abnormalities, and the bone age, according to Greulich and Pyle, was 7 years for a chronological age of 8.2 years. There was no other detailed information about her growth velocity and management. By the time the patient presented to CWEC, she had not been taking any prescribed or over-the-counter medications for about a year. She was a fifth grade student and a bit behind her class. She was short and slim, with height of 118 cm. Height standard deviation score (SDS) was −3.3 and weight was 19 kg. Her mother's height was 159.5 cm and father's height was 167cm. Mid-parental height (MPH) = (mother’s height + father’s height/2) − 6.5 cm = 156.75 cm Target height (TH) = 161.25 cm (calculated by Tanner’s method with an additional correction for secular trend = MPH + 4.5 cm) []. TH SDS was −0.3. The difference between TH SDS and patient height SDS was –3 SD. On the first consultation, the vital signs were normal (blood pressure 90/60 mmHg, heart rate 98 beats per minute, and temperature 36.8 °C). Physical examination indicated mild retrognathia and micrognathia. The parents claimed that the face was similar to that of her paternal grandmother. She had no signs of puberty. Neurological evaluation and other aspects of physical examination including chest, heart, abdomen, extremities, and genitalia were normal. Initially, we took into account her being small for gestational age (SGA) at birth (low birth weight and height SDS < −1.88 after the age of 2 years []), being unable to reach the normal growth chart since the age of 4 years, and having had two unresponsive provocative GH tests, and diagnosed her with SGA without catch-up growth. She was started on GH [somatropin (NordiLet pen 5 mg/1.5 mL) 35 mcg/kg/day, subcutaneous injections seven nights per week]. She was also put on a regimen of multivitamins (Nature Made Multivitamin Complete tablet), one tablet six times per week. Kidney, liver, and thyroid function, complete blood count, biochemistry, urinalysis, and celiac disease studies were again requested and were all with normal ranges. One year after being on this treatment cocktail, the height velocity had not improved according to our expectations. Height SDS was −3.4, and increment in height SDS was −0.1. At this time, we performed another physical examination and found that the patient had a high arched palate and low posterior hairline. She had no other somatic signs of TS including short neck, scoliosis, cubitus valgus, short fourth metacarpal or metatarsal bone, or Madelung deformity. The next and final step of our investigation was to request karyotype screening, which confirmed a diagnosis of TS, even though her karyotype was not typical of TS. Twenty-one metaphase spreads were studied based on the trypsin-Giemsa G-band (GTG) technique at 400–550-band resolution. Chromosome analysis revealed an abnormal female chromosome complement in all cells examined with a single X chromosome and a balanced Robertsonian translocation between the long arms of chromosomes 13 and 14. The result showed TS with 44,X,der(13;14)(q10;q10) karyotype. Karyotype studies of the parents and the only sibling (the patient's 6-year-old sister) were requested. Karyotype analysis of the mother and sister were normal (46,XX), but the father's analysis showed a balanced Robertsonian translocation between the long arms of chromosomes 13 and 14, similar to the patient’s [45,XY,der(13;14)(q10;q10)]. It appeared that the balanced translocation was transmitted from the father. We did not determine whether the origin of the single X chromosome was paternal or maternal. When the TS diagnosis was confirmed at the age of 11.9 years, we increased the dose of GH to 50 mcg/kg/day, and oral oxandrolone (0.04 mg/kg/nightly) was added to the treatment. Cardiac and renal evaluations were normal. Her annual blood pressure measurements were within the normal range (on average 85/60 mmHg). Abdominal sonography demonstrated a rudimentary uterus, and ovaries were not visible. The patient was reviewed every 6 to 12 months, and her height, weight, and growth velocity were measured, in addition to general physical examination and assessment of the recent blood results. In the first 15 months of her treatment and follow-up, her height increased 6 cm. The increase in height SDS was −0.5 SD, which was not sufficient. Once again, we checked thyroid function and serum anti-tissue transglutaminase (TTG) immunoglobulin A (IgA), and performed fecal tests to detect any evidence of autoimmune thyroid, celiac, or inflammatory bowel diseases. All the results were within the normal range. By then, she was 14 years old, with height of 137 cm (SDS = −3.6) and weight of 31 kg. The height increment in the second year of treatment was +0.3 SD. This young girl is still on GH (NordiLet pen 50 mcg/kg/day) and oxandrolone treatment. We have not yet started her on estrogen replacement therapy, as the ultimate height increase was the first concern, but it will be considered in our next step of treatment. The last bone age measurement, according to Greulich and Pyle, was 11.9 years, with chronological age of 13.5 years. If the diagnosis had been made earlier and the GH had started with a higher dose from the beginning, her height would be predicted to be taller []. When the condition was discussed with her parents, they became anxious and were in denial at first. Later on, they accepted the situation, especially when the syndrome characteristics were explained to them in full detail. They were very cooperative, and encouraged their daughter to attentively take the medications. However, the parents decided to not inform the patient of the exact diagnosis, as they were worried it might affect her mental health. Although both the patient and her parents were unhappy and disappointed that it took more than a decade for the diagnosis to be clarified, despite the fact that they were frequently seeking medical attention, they acknowledged that TS is not a common condition, and were there higher awareness of the symptoms and diagnosis of this syndrome among physicians, particularly endocrinologists, it could have been managed earlier and the outcome would be more acceptable.