ESPE Abstracts

Introduction: Interstitial deletions on the long arm of the 12th chromosome are rare and often occur de novo. These deletions have been found to be associated with mental retardation, developmental delay, growth retardation and various congenital anomalies in different studies. In studies up to date, it has been determined all interstitial 12q deletions are clustered between five regions on this chromosome (HMGA2, GRIP1, LEMD3, MSRB3, and TMBIM4). Low birth weight, failure to catch up growth, short stature, learning difficulties, Buschke–Ollendorff lesions on skin and bone (ostepoikilosis in the non-sensitive, tight skin and long bone epiphysis and metaphyses, wrist, foot, elbow, pelvis and scapula) has been reported in 12q14 microdeletion syndrome. Located within the 12q14 microdeletion region;it has been reported that LEMD3 haploinsufficiency is responsible for skin and bone lesions and heterozygous HMGA2 deletion is responsible for growth retardation. Up to date different phenotypes of 12q deletions have been described in a total of 69 patients. Here a case followed up in our clinic due to pathological short stature and detected to have 2.7 Mb deletion in 12q14.2 region in microarray analysis will be presented.

Case: A three-year-old female patient with short stature was referred to our outpatient clinic. She was born from a consanguineous marriage at 37 weeks of gestational age and with 2600g birthweight. Her mother had hypothyroidism, father had diabetes and she had two healthy siblings. She was evaluated in gastroenterology division and using enteral nutrition currently. Anthropometric measurements were determined as; weight: 6.3 kg (-3.28 SDS), height: 61 cm (-5.12 SDS), BMI:16.93 kg/m2 (0.24 SDS), target height:151.15 cm (- 2.04 SDS). In physical examination;frontal bossing, high palate, small mouth, clinodactyly at the 5th finger of the left hand, short neck, hypoplasic midface, bulbous nasal tip, thin lower lip and pointed fingertips were detected. In laboratory examinations, nutritional tests were normal, IGF-1:126 ng/ml (-1/mean SDS) and IGFBP-3: 3460 ng/ml (+1/+2 SDS). Bone age was evaluated as newborn. Peak growth hormone response to the growth hormone stimulation test (with clonidine) was sufficient (Peak:15.6 ng/mL). Bone survey was reported as normal. No organ pathology was detected in echocardiography and abdominal ultrasonography. Karyotype was reported as 46,XX.MLPA analysis for Russell-Silver syndrome was normal.A deletion of 2.7 Mb was detected in 12q14.2 region in microarray analysis performed in follow-up.

Conclusion: 12q deletions may present with pathological short stature and reinterpretation of microdeletions may help us understand the growth-related mechanisms of our experience of genotype&phenotype relationship better in affected individuals.