Prenatal diagnosis and neonatal phenotype of a de novo microdeletion of 17p11.2p12 associated with Smith–Magenis syndrome and external genital defects

Smith–Magenis syndrome (SMS, OMIM: 182290) is a multiple congenital anomalies and intellectual disability syndrome due to a 3.45 Mb microdeletion involving 17p11.2 and is estimated to occur about one in 25,000 births. Up to now, the ultrasound findings of the foetus with SMS and their external genital defects in patients are rarely reported. This case indicates that foetus with SMS may present polyhydramnios and ventriculomegaly in the second trimester. The newborn male patient had an abnormal phenotype in which he has micropenis and his anus is close to the perineal body. The identification of this case may further expand the phenotypic spectrum of this genetic disorder.

Fetal Smith-Magenis syndrome diagnosed after pregnancy termination by low-coverage whole-genome sequencing: a report of two cases / 中华围产医学杂志

We reported two fetal cases diagnosed with Smith-Magenis syndrome.One case was found with bilateral ventriculomegaly,double-outlet right ventricle,pulmonary stenosis and ventricular septal defect when performing fetal echocardiography.Then the fetus was diagnosed with severe tetralogy of Fallot and tortuous ductus arteriosus by autopsy.The other case was suggested to have tetralogy of Fallot,right aortic arch and ectopic ductus arteriosus by fetal echocardiography,which was later confirmed by autopsy.Both of the two pregnancies were terminated.Tissue samples of the two fetuses were analyzed by the low-coverage whole-genome sequencing,and both cases carried a microdeletion of 3.63 Mb and 4.86 Mb in chromosome 17pl 1.2,which overlapped with the missing segments causing Smith-Magenis syndrome.Therefore,the two fetuses were both diagnosed with Smith-Magenis syndrome.

Research on the Diagnosis of Smith-Magenis Syndrome / 中山大学学报(医学科学版)

[Objective] We explore the diagnosis of Smith-Magenis syndrome and its clinical features of children,to raise the domestic awareness of this disease.[Methods] In this study,the child received peripheral blood chromosome microarray analysis,blood routine and urine routine,growth hormone provocation test,insulin-like growth factor Ⅰ and insulin-like growth factor binding protein Ⅲ test,cortisol (8a) test,prolactin test,adrenocorticotropic hormone test,thyroid function test,liver and kidney function test,blood biochemistry test,fasting insulin test,2-hour plasma glucose test,the antibodies and antigens test of hepatitis B.The bone age measurement and the pituitary gland MRI were also performed.We use the above figures to diagnose Smith-Magenis syndrome,assess and observe the condition of the child in Smith-Magenis syndrome.[Results] In this case,the chromosomal microarray analysis revealed a deletion of about 3.6Mb fragments in the chr17p11.2 region,including main functional gene RAI1,which was associated with Smith-Magenis syndrome.According to the clinical manifestations and the result of chromosome microarray analysis,the diagnosis of children with Smith-Magenis syndrome was made clear.[Conclusion] Genetic tests are the standard for diagnosing Smith-Magenis syndrome.When children have special facial features combined with multiple system disorders,early genetic examination is conducive to early diagnosis,and can reduce the time and economic cost.

A Case of Smith-Magenis Syndrome with Multiple Organ Malformations

Smith-Magenis syndrome (SMS) is a genetic disease caused by microdeletion of p11.2 in chromosome 17. SMS patients have characteristic facial features and accompanying congenital malformations involving the brain, cardiovascular system, and urinary tract. Compared with the distinctive facial characteristics, organ malformations are less common. Several cases of SMS with tetralogy of Fallot have been reported in Korea, none of which were accompanied by other organ malformations. We present the first case report in Korea of an SMS patient with malformations of the brain, heart, and urinary tract.

Reciprocal Deletion and Duplication of 17p11.2-11.2: Korean Patients with Smith-Magenis Syndrome and Potocki-Lupski Syndrome

Deletion and duplication of the -3.7-Mb region in 17p11.2 result in two reciprocal syndrome, Smith-Magenis syndrome and Potocki-Lupski syndrome. Smith-Magenis syndrome is a well-known developmental disorder. Potocki-Lupski syndrome has recently been recognized as a microduplication syndrome that is a reciprocal disease of Smith-Magenis syndrome. In this paper, we report on the clinical and cytogenetic features of two Korean patients with Smith-Magenis syndrome and Potocki-Lupski syndrome. Patient 1 (Smith-Magenis syndrome) was a 2.9-yr-old boy who showed mild dysmorphic features, aggressive behavioral problems, and developmental delay. Patient 2 (Potocki-Lupski syndrome), a 17-yr-old boy, had only intellectual disabilities and language developmental delay. We used array comparative genomic hybridization (array CGH) and found a 2.6 Mb-sized deletion and a reciprocal 2.1 Mb-sized duplication involving the 17p11.2. These regions overlapped in a 2.1 Mb size containing 11 common genes, including RAI1 and SREBF.

Two cases of Smith-Magenis syndrome / 소아과

SmithMagenis syndrome (SMS) is a rare disorder with multiple congenital anomalies caused by a heterozygous interstitial deletion involving chromosome 17p11.2, where the retinoic acid-induced 1 (RAI1) gene is located, or by a mutation of RAI1. Approximately 90% of the patients with SMS have a detectable 17p11.2 microdeletion on fluorescence in-situ hybridization (FISH). SMS is characterized by mental retardation, distinctive behavioral features, craniofacial and skeletal anomalies, speech and developmental delay, and sleep disturbances. Although there are some intervention strategies that help individuals with SMS, there are no reported specific interventions for improving the outcome in children with SMS. Here, we report two cases of SmithMagenis syndrome.

Two Cases of Smith-Magenis Syndrome with Tetralogy of Fallot Confirmed by FISH / 대한진단검사의학회지

Smith-Magenis syndrome (SMS) is characterized by distinctive facial features, developmental delay, cognitive impairment, and behavioral abnormalities and associated with interstitial deletion of chromosome 17p11.2. We report 2 cases of SMS with tetralogy of Fallot. The first patient was reported having a normal conventional karyotype 7 years ago. However, as she grew up, she showed more compatible findings with SMS in behavior and phenotype. On the second cytogenetic study, interstitial deletion of 17p11.2 was detected by conventional banding technique which had 550 band resolution and it was confirmed by metaphase fluorescence in situ hybridization (FISH) using D17S258 SMS probe (Oncor, Gaithersburg, MD, USA). The second patient showed subtle phenotypic feature except microcephaly and cardiac anomalies was confirmed as SMS by cytogenetic analysis and FISH. We suggest that FISH should be performed not to overlook the submicroscopic deletion when SMS is clinically suspected, even though cytogenetist can not detect any anomalies on the conventional cytogenetics. A confirmatory diagnosis using FISH would be helpful in terms of guiding medical management and leading to proper genetic counseling.