Miller-Dieker Syndrome with der(17)t(12;17)(q24.33;p13.3)pat Presenting with a Potential Risk of Mis-identification as a de novo Submicroscopic Deletion of 17p13.3 / 대한진단검사의학회지

Miller-Dieker syndrome involves a severe type of lissencephaly, which is caused by defects in the lissencephaly gene (LIS1). We report the case of a female infant with der(17)t(12;17)(q24.33;p13.3)pat caused by an unbalanced segregation of the parental balanced translocation of 17p with other chromosomes. The proband presented with facial dysmorphism, arthrogryposis, and intrauterine growth retardation. Most cases of Miller-Dieker syndrome have a de novo deletion involving 17p13.3. When Miller-Dieker syndrome is caused by an unbalanced translocation, mild-to-severe phenotypes occur according to the extension of the involved partner chromosome. However, a pure partial monosomy derived from a paternal balanced translocation is relatively rare. In this case, the submicroscopic cryptic deletion in the proband was initially elucidated by FISH, and karyotype analysis did not reveal additional chromosome abnormalities such as translocation. However, a family history of recurrent pregnancy abnormalities strongly suggested familial translocation. Sequential G-banding and FISH analysis of the father's chromosomes showed that the segment of 17p13.3-->pter was attached to the 12qter. Thus, we report a case that showed resemblance to the findings in cases of a nearly pure 17p deletion, derived from t(12;17), and delineated by whole genome array comparative genomic hybridization (CGH). If such cases are incorrectly diagnosed as Miller-Dieker syndrome caused by de novo 17p13.3 deletion, the resultant improper genetic counseling may make it difficult to exactly predict the potential risk of recurrent lissencephaly for successive pregnancies.

The clinical phenotype of the derivative (8)t(7;8)(q22;p23.3) in two siblings / 소아과

We report on 2 siblings with a partial trisomy of 7q (7q22-->qter) and concomitant partial monosomy of 8p (8p23.3-->pter), which were shown by FISH using probes located at the telomere region of each chromosome. All the balanced translocation carriers (father and a sister) in this family had a normal phenotype. The 2 siblings with the same abnormal karyotype had similar multiple congenital anomalies and dysmorphic features. During the follow-up, the first male patient died in the neonatal period, but the female sibling is still alive at 2 years and 6 months of age.

A Case of Partial Monosomy 10q with Partial Trisomy 22q due to Maternal Balanced Translocation

Partial monosomy of chromosome 10q is a rare chromosomal anomaly. Most cases of partial deletion 10q have chromosome breakpoints in the 10q25 or 10q26 region. Recently about 30 cases with breakpoint in the 10q26 region have been reported. Partial trisomy of chromosome 22q is also a rare chromosomal anomaly. Most cases of partial duplication 22q are 22q proximal segment duplications known as Cat-eye syndrome. The other cases, 22q11.2 microduplications and 22q distal long arm (22qter) duplications, are also reported but exceedingly rare. We experienced a male neonate who had facial dysmorphisms, congenital heart defect and cryptorchidism. His chromosomal analysis revealed an deletion of chromosome 10q26.1-->qter and duplication of chromosome 22q11.2-->qter caused by maternal balanced translocation e.g. partial monosomy 10q and partial trisomy 22q. Although some cases of partial monosomy 10q were accompanied by other chromosomal abnormalities, this combination of chromosomal abnormalities has not been reported in the literature.

A Case of 2q-Syndrome 46, XX, del (2) (q33q35)

A long arm deletion of chromosome 2 is very rarely reported. Particular deletion uniformly resulted in developmental delays, craniofacial changes, and occasionally resulted in microcephaly, low set ears, and hand and foot abnormalities. We experienced a case of partial monosomy 2 in a 5-months-old girl, who showed low set ears, hypertelorism, low nasal bridges, small mouth, cleft palate, inguinal hernia. Chromosome analysis on a G banding with high resolution showed a deletion of the long arm of chromosome 2. Her karyotype was designated as 46, XX, del (2) (q33q35). A brief review of the literature is also presented.

A Case of Partial Monosomy lOq Syndrome

It has been estimated that chromosomal aberrations account for 2.3% to 3% of normal pregnancies and of them 85% are aborted. Therefore, the survival rate of neonates with chromosomal aberrations are very low. Patients with partial deletion of the long arm of chromosome 10 are rare. We experienced a case of partial monosomy 10 in a 14-years-old girl. She showed mental and growth retardation, low-set malformed ears, hyperterolism, hypothyroidism and dilated cardiomyopathy. Chromosomal analysis on G-banding with high resolution showed a terminal deletion of the long arm of chromosome 10. Her karyotype was designated as 46, XX, del (l0) (q26). A brief review of literature is also presented.