PMC7076151_01
(A,B) Photograph of the patient. (C) Chest radiography of the patient. Thoracic dysplasia (bell-shaped small thorax with coat-hanger appearance). (D) Anterior abdominal wall defect with bowel herniation consistent with history of omphalocele. (The written informed consent was obtained from the parents of the patient for the publication of this image).
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F1
On physical examination at birth, dysmorphic facial features were noted including narrow forehead, frontal bossing, short palpebral fissures, depressed nasal bridge, anteverted nares, elongated philtrum, low-set posteriorly rotated ears, and micrognathia (Figures 1A,B). Abdominal ultrasound showed left-sided mild hydronephrosis, and skeletal survey displayed 11 pairs of ribs and bell-shaped thoracic cavity with coat-hanger looking ribs (Figures 1C,D).
(A) Karyotype of the patient. (B) Microsatellite analysis. Maternally and paternally derived peaks are showed, respectively. (C) The short tandem repeats (STRs) on the long arm of chromosome 14 analyzed along with their position (hg19 map). (D) Result of SNP-Array. Homozygous regions in chromosome 8 and 11 were identified (Top); No homozygous region in chromosome 14 was detected (Bottom). (E) Schematic representation of the trisomy rescue (TR) mechanism leading to the heterodisomy upd(14)pat. A nondisjunction event between two chromosomes 14 occurred when a male ROB carrier produce a sperm. The segregation of the chromatids determined the formation of sperm with a ROB and a free chromosome 14. Oocyte has one of each normal chromosome 13 and 14. Then, after fertilization, there would be three chromosome 14 in the zygote. In order to avoid cell death of the three chromosome 14, the normal chromosome 14 from the mother will be excluded through the process of post-zygotic TR, which could result in paternal heterodisomy in the early embryo.
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F2
Due to his multiple congenital anomalies, routine chromosome analysis was performed on peripheral blood and the results revealed an abnormal male karyotype with a balanced ROB:45,XY,der(13;14)(q10;q10) (Figure 2A). All three markers demonstrated that the patient inherited two homologous chromosome 14 from his father, confirming a paternal uniparental heterodisomy of 14q (Figures 2B,C). The test identified two homozygous regions with varied molecular sizes but did not detect any clinically relevant copy number change (Figure 2D).