Subtelomeric analysis detects a familial 10p;12p rearrangement in two relatives with a distinct syndrome

A new partial trisomy 12p with artery catheter vagus, congenital cataracts, external auditory canal, and no turbinate

We describe the prenatal diagnosis and fetal phenotype of partial trisomy 12 (p12-pter) transmitted from a maternal reciprocal translocation 6;12. Genetic analysis was conducted on umbilical cord blood for a fetus accompanied with tricuspid regurgitation and orbital hypertelorism from a 27-year-old gravida 4, para 1 after sonography at gestation 35 weeks. The karyotype was unusual, with 46, XY, der (6), t (6;12) (p24; p12) mat. The pregnancy was terminated at 37 gestational weeks. The aborted fetus displayed dysmorphic features of a round flat face with prominent cheeks and high forehead, hypertelorism, short nose, broad and depressed nasal bridge, anteverted nares, deformed philtrum, open mouth, thin upper vermilion and broad everted lower lip, low-set ears and aural atresia, broad hands with simian creases, and a short neck. Fetal anatomy showed right artery catheter vagus, congenital cataract, no turbinate and external auditory canals. Through karyotype-phenotype analysis of this patient and a review of other reported cases, we believe this is a first report that expands the database of partial trisomy 12p, and is beneficial for future clinical genetic counseling. This study supports that phenotypic variability depends on the type and extent of the associated partial monosomy.

Duplication of the Miller-Dieker Critical Region in a Patient with a Subtelomeric Unbalanced Translocation t(10;17)(p15.3;p13.3)

Submicroscopic duplications in the Miller-Dieker critical region have been recently described as new genomic disorders. To date, only a few cases have been reported with overlapping 17p13.3 duplications in this region. Also, small deletions that affect chromosome region 10p14→pter are rarely described in the literature. In this study, we describe, to our knowledge for the first time, a 5-year-old female patient with intellectual disability who has an unbalanced 10;17 translocation inherited from the father. The girl was diagnosed by subtelomeric FISH and array-CGH, showing a 4.43-Mb heterozygous deletion on chromosome 10p that involved 14 genes and a 3.22-Mb single-copy gain on chromosome 17p, which includes the critical region of the Miller-Dieker syndrome and 61 genes. The patient's karyotype was established as 46,XX.arr 10p15.3p15.1(138,206-4,574,436)x1,17p13.3(87,009-3,312,600)x3. Because our patient exhibits a combination of 2 imbalances, she has phenotypic features of both chromosome abnormalities, which have been reported separately. Interestingly, the majority of patients who carry the deletion 10p have visual and auditory deficiencies that are attributed to loss of the GATA3 gene. However, our patient also presents severe hearing and visual problems even though GATA3 is present, suggesting the involvement of different genes that affect the development of the visual and auditory systems.

Combined partial trisomy 11q and partial monosomy 10p in a 19-year-old female patient: phenotypic and genotypic findings

Constitutional partial trisomy 11q in man mostly occurs in combination with partial trisomy 22 due to a balanced parental translocation t(11;22). Occasionally a chromosome other than 22 is involved in the parental translocation with chromosome 11, resulting in partial monosomy for the other participating chromosome. We report of a patient with partial trisomy 11q and partial monosomy 10p [46,XX,der(10)t(10;11)(p15;q22)] due to a paternal balanced translocation [46,XY,t(10;11)(p15;q22)]. Array CGH showed heterozygosity for a deletion of ∼3.46 Mb at 10p15.3p15.2 and gain of ∼32.21 Mb at 11q22.2q25. The patient, a 19-year-old woman, has a multiple congenital anomaly syndrome with severe developmental and growth delay, muscular hypotonia, iris coloboma, abnormal external ears, widely spaced nipples, atrial septum defect, clubfoot, and arthrogryposis multiplex congenita. Despite multiple health problems and numerous hospitalizations due to massive seizures, pulmonary insufficiency and recurrent infections the patient reached adulthood. The clinical features in our patient are compared to other cases reported in the literature of either partial monosomy 10p or partial trisomy 11q. To the best of our knowledge, this is the first report of the combination of partial trisomy 11q and partial monosomy 10p. Comparing the molecular karyotype and the phenotype of our patient to other patients, the clinical features of our patient are more likely due to partial trisomy 11q than to partial monosomy 10p.