Introduction: Derivative chromosome is a rearrangement involving two or more chromosomes or the presence of multiple abnormalities in a single chromosome and always contains intact centromere. Segmental anomalies such as inversion or translocation in derivative chromosome may result in partial duplication or deletion during meiosis. Chromosomal translocations usually result in miscarriage and multiple anomalies (common neurodevelopmental defects, growth retardation, severe malnutrition, reproductive failure, cardiac anomalies) are observed in newborns. Here, a case of derivative chromosome 1 accompanied by deletion in Y-chromosome will be presented.
Case: A 17-year-old male patient first entered our follow-up at the age of 12. He was born with term NSVY of 1800 g, followed up in incubator for 15 days after birth, operated for hydrocele-hernia-undescended testis-cleft palate-tracheostomy, immobile due to widespread neurodevelopmental retardation, had feeding problems and intermittent catheterization due to neurogenic bladder. He also had levothyroxine replacement for primary hypothyroidism, multiple antiepileptics for epilepsy and had no parental consanguinity or similar disease in his family members. In physical examination, pathological short stature and severe malnutrition, hypertelorism, nasal root depression, low ear, narrow forehead, low nape hairline, micro-retrognathia, cleft palate operation scar, drop foot, hypospadias, flexion contracture of fingers were detected. He was prepubertal and testicles were bilateral atrophic at inguinal canal. AFP-beta HCG-AMH-inhibin B levels were normal. Reorchiopexy was applied in follow-up. His imaging showed corpus callosum agenesis and intermittent anterior pituitary hormone levels were normal. In the follow-up severe osteoporosis was detected in patient who developed femur fracture during physotheraphy and pamidronate treatment was given. There was no pituitary problem in LHRH stimulation test of the patient who had hypogonadotropic hypogonadism. Testosterone and vitamin D replacements were treated. Karyotype was reported as 45,X, der(1)(inv 1)(p13q44) t(1;4)(q44;p11). In microarray analysis deletion of 1,786 kb in 1p12, 6,912kb in 1q43q44 and 10,800kb in Yq11,221q11.23. was detected. In Y-microdeletion analysis, deletions were detected in AZFb, AZFc-d, AZFc-DAZ regions of Y chromosome and SRY was positive. The patient wasn’t considered to be as mixed gonadal dysgenesis or Turner syndrome variant and the genetic pathology didn’t pose an additional risk of gonadal tumors. Close follow-up of the case was decided.
Conclusion: Our case provides information about mutation spectrum of Y-autosomal translocation associated with dysmorphology. There is still more need to increase our observations about this spectrum.
15 Sep 2022 - 17 Sep 2022