Gastrointestinal disorders in Down syndrome

Down syndrome is the most common human chromosomal disorder. Among clinical findings, one constant concern is the high prevalence of gastrointestinal system alterations. The aim of this study was to determine the prevalence of gastrointestinal disorders at a Down syndrome outpatient clinic during a 10‐year follow‐up period. Data from medical files were retrospectively reviewed from 1,207 patients. Gastrointestinal changes occurred in 612 (50.7%). The most prevalent disorder was chronic intestinal constipation. Intestinal parasite occurred in 22% (mainly giardiasis), gastroesophageal reflux disease in 14%, digestive tract malformations occurred in 5%: 13 cases of duodenal atresia, 8 of imperforate anus, 4 annular pancreases, 2 congenital megacolon, 2 esophageal atresias, 2 esophageal compression by anomalous subclavian and 1 case of duodenal membrane. We had 38/1,207 (3.1%) patients with difficulty in sucking and only three with dysphagia that resolved before the second year of life. Peptic ulcer disease, celiac disease, and biliary lithiasis were less prevalent with 3% each. Awareness of the high prevalence of gastrointestinal disorders promotes outstanding clinical follow‐up as well as adequate development and greater quality of life for patients with Down syndrome and their families.     

Clinical and molecular study in congenital muscular dystrophy with partial laminin alpha 2 (LAMA2) deficiency

Complete laminin alpha2 (LAMA2) deficiency causes approximately half of congenital muscular dystrophy (CMD) cases. Many loss-of-function mutations have been reported in these severe, neonatal-onset patients, but only single missense mutations have been found in milder CMD with partial laminin alpha2 deficiency. Here, we studied nine patients diagnosed with CMD who showed abnormal white-matter signal at brain MRI and partial deficiency of laminin alpha2 on immunofluorescence of muscle biopsy. We screened the entire 9.5 kb laminin alpha2 mRNA from patient muscle biopsy by direct capillary automated sequencing, single strand conformational polymorphism (SSCP), or denaturing high performance liquid chromatography (DHPLC) of overlapping RT-PCR products followed by direct sequencing of heteroduplexes. We identified laminin alpha2 sequence changes in six of nine CMD patients. Each of the gene changes identified, except one, was novel, including three missense changes and two splice-site mutations. The finding of partial laminin alpha2 deficiency by immunostaining is not specific for laminin alpha2 gene mutation carriers, with only two patients (22%) showing clear causative mutations, and an additional three patients (33%) showing possible mutations. The clinical presentation and disease progression was homogeneous in the laminin alpha2-mutation positive and negative CMD patients.     

以造影增强磁共振血管成像术诊断先天性主动脉弓畸形

目的评价造影增强磁共振血管成像术（CE-MRA）对先天性主动脉弓畸形的诊断准确性并与超声心动图等比较。方法413例先天性主动脉弓畸形病例在1999年4月到2004年12月期间做了CE-MRA检查。年龄5d～11岁，平均年龄2.4岁。检查使用1.5T磁共振扫描仪。对比剂gadolinium-DTPA，剂量0.2mmol／kg体质量，手动静脉注射。磁共振检查前均已做心脏超声检查。结果在413例中，动脉导管未闭（PDA）166例，主动脉缩窄（COA）168例，主动脉弓中断（IAA）31例，双主动脉弓等其他先天性主动脉弓畸形48例。全部413例均经手术和／或X线心血管造影证实。CE-MRA的诊断准确率为97.3％（402／413），心脏超声检查的诊断准确率为87.2％（360／413）。结论对于先天性主动脉弓畸形，CE-MRA是可靠的影像学检查方法，不仅优于心脏超声检查，有时CE-MRA甚至能比传统的X线心血管造影术提供更多的诊断信息。     

Retrospective analysis of fetal vertebral defects: Associated anomalies,etiologies, and outcome

Our objectives were to describe fetal cases of vertebral defects (VD), assess the diagnostic yield of fetal chromosomal analysis for VD and determine which investigations should be performed when evaluating fetal VD. We performed a retrospective chart review for fetuses with VD seen between 2006 and 2015. Cases were identified from CHU Sainte‐Justine's prenatal clinic visits, postmortem fetal skeletal surveys, and medical records. Cases with neural tube defects were excluded. Sixty‐six fetuses with VD were identified at a mean gestational age of 20 weeks. Forty‐seven (71.2%) had associated antenatal anomalies, most commonly genitourinary, skeletal/limb, and cardiac anomalies. Thirteen mothers (19.7%) had pregestational diabetes (95% CI [10.1%–29.3%]). Fifty‐three cases had chromosomal analysis. Three had abnormal results (5.6%): trisomy 13, trisomy 22, and 9q33.1q34.11 deletion. Thirty‐four (51.5%) pregnancies were terminated, one led to intrauterine fetal demise and 31 (46.9%) continued to term. Of 27 children who survived the neonatal period, 21 had congenital scoliosis and 3 had spondylocostal dysostosis. Seven had developmental delay. In conclusion, prenatal evaluation of fetuses with VD should include detailed morphological assessment (including fetal echocardiogram), maternal diabetes screening, and chromosomal microarray if non‐isolated. Our findings provide guidance about management and counseling after a diagnosis of fetal VD.     

先天性三尖瓣畸形及其功能影响

在１５６例先天性心血管畸形标本的观察和测量中，检出先天性三尖瓣畸形２５例（１６．０２％），其中Ｅｂｓｔｅｉｎ＇ｓ畸形６例，三尖瓣发育不良１４例，三尖瓣缺如１例，三尖瓣瓣叶或／和腱索骑跨４例。用测量及比较解剖学的方法探求三尖瓣畸形与其功能的影响。结果显示：Ｅｂｓｔｅｉｎ＇ｓ畸形和三尖瓣发育不良的心脏构筑都有明显的变化，而且两者存在一定的差异，同时明确了Ｅｂｓｔｅｉｎ＇ｓ畸形的病理诊断标准和三尖瓣发育不良的分类。     

Fetal cervical hyperextension in arthrogryposis

Perhaps the most dramatic position of a newborn after delivery is when there is hyperextension of the neck and spine. It will have been presented in utero and today, almost always, such babies will have been delivered by C‐section. The associated anomalies are variable. The process(es) that can lead to cervical hyperextension is/are largely unknown. The outcome is variable from lethal to completely resolve. Individuals with arthrogryposis and in particular with Amyoplasia appear to have an increased frequency of neck, cervical, and spine hyperextension at birth. We present here 41 cases of arthrogryposis (mainly Amyoplasia) with fetal cervical hyperextension. The outlook is surprisingly good if spinal cord trauma does not occur. Ultrasound late in pregnancy when arthrogryposis is recognized prenatally should determine whether cervical hyperextension has developed, so that appropriate preventive measures can be taken.     

Reciprocal translocation mosaicism in man

We report on an8-month-old girl with a de novo 5q/6q autosomal translocation with loss of the distal part of the long arm of chromosome 6 (6q23.3→6qter); clinical manifestations are peculiar craniofacial stigmata, truncal obesity and persisting hypotonia. The similarity with a previously reported patient with 6q interstitial deletion is discussed.     

Other genomic disorders and congenital heart disease

Congenital heart disease (CHD) is the common birth defect worldwide. Despite its recognized burden on public health, the etiology in the vast majority of individuals remains unknown. Chromosomal abnormality plays an important role, frequently observed as large cytogenetically visible rearrangement or small submicroscopic structural variation in the genome. Several genomic disorders are now recognized that are increasingly responsible for CHD with variable penetrance. Single gene disorders, epigenetic alterations, and environmental etiologies are also significant contributors. Our understanding of the genetic basis of CHD has increased exponentially with the escalating use of next generation sequencing to identify ever so small submicroscopic genomic imbalances at the level of coding exons in CHD. This review focuses on genomic disorders other than 22q11.2 deletion, that are major players in the etiology of human cardiac malformations.     

Female‐restricted syndromic intellectual disability in a patient from Thailand

Female‐restricted syndromic intellectual disability (ID) is a neurodevelopmental disorder with developmental delay (DD)/ID, facial dysmorphism, and diverse congenital anomalies comprising heart defects, anal anomalies, choanal atresia, postaxial polydactyly, scoliosis, and brain abnormalities. Loss‐of‐function mutations in the USP9X gene inherited as X‐linked dominance were identified as its etiology in females of different ethnic groups. Here, we report a 15‐year‐old Thai girl harboring a novel de novo heterozygous one‐base pair deletion (c.3508delG, p.Val1170TrpfsX9) in exon 23 of USP9X. Her profound DD, dysmorphic face including attached earlobes, short stature, and congenital malformations including s‐shaped thoracolumbar scoliosis, hip dislocation, and generalized brain atrophy shared common characteristics of X‐linked syndromic ID. We have observed severely malformed oro‐dental organs and a choledochal cyst, which have never been reported. Our study presents the first patient from Thailand expanding the phenotypic and mutational spectra of the syndrome.