Atrioventricular canal defect and postaxial polydactyly indicating phenotypic overlap of Ellis-van Creveld and Kaufman-McKusick syndromes

The health-care utilization and economic burden in patients with genetic skeletal disorders

BACKGROUND

Most genetic skeletal disorders (GSD) were complex, disabling and life-threatening without effective diagnostic and treatment methods. However, its impacts on health system have not been well studied. The study aimed to systematically evaluate the health-care utilization and economic burden in GSD patients.

METHODS

The patients were derived from 2018 Nationwide Inpatient Sample and Nationwide Readmissions Database. GSD patients were extracted based on International Classification of Diseases-10th revision codes.

RESULTS

A total of 25,945 (0.12%) records regarding GSD were extracted from all 21,400,282 records in NIS database. GSD patients were likely to have significantly longer length of stay (6.50 ± 0.08 vs. 4.63 ± 0.002, P < 0.001), higher total charges ($85,180.97 ± 1,239.47 vs. $49,884.26 ± 20.99, P < 0.001), suffering more procedure, diagnosis and transferring records in comparison to patients with common conditions. GSD patients had a significantly higher 30-day all-cause readmission rate based on Nationwide Readmissions Database.

CONCLUSIONS

The heavy health-care utilization and economic burden emphasized the urgency for policy leaders, scientific and pharmaceutical researchers, health care providers and employers to identify innovative ways and take effective measurements immediately, and eventually to help improve the care, management, and treatment of these devastating diseases.

Atrioventricular canal defect and genetic syndromes: The unifying role of sonic hedgehog

The atrioventricular canal defect (AVCD) is a congenital heart defect (CHD) frequently associated with extracardiac anomalies (75%). Previous observations from a personal series of patients with AVCD and "polydactyly syndromes" showed that the distinct morphology and combination of AVCD features in some of these syndromes is reminiscent of the cardiac phenotype found in heterotaxy, a malformation complex previously associated with functional cilia abnormalities and aberrant Hedgehog (Hh) signaling. Hh signaling coordinates multiple aspects of left-right lateralization and cardiovascular growth. Being active at the venous pole the secondary heart field (SHF) is essential for normal development of dorsal mesenchymal protrusion and AVCD formation and septation. Experimental data show that perturbations of different components of the Hh pathway can lead to developmental errors presenting with partially overlapping manifestations and AVCD as a common denominator. We review the potential role of Hh signaling in the pathogenesis of AVCD in different genetic disorders. AVCD can be viewed as part of a "developmental field," according to the concept that malformations can be due to defects in signal transduction cascades or pathways, as morphogenetic units which may be altered by Mendelian mutations, aneuploidies, and environmental causes.

Hydrometrocolpos etiology and management: past beckons the present

Hydrometrocolpos is a rare condition in which the uterus and the vagina are grossly distended with a retained fluid other than pus or blood. It may present during the neonatal period or later at puberty. Most cases reported earlier were stillbirths and were diagnosed only on autopsy. Antenatal diagnosis is now possible with the advent of ultrasound. An early diagnosis and speedy management is the key to survival. Many previous case reports have focused on the varied clinical presentations, multiple causes, associated syndromes and/or the radiological diagnosis of this condition. However, management options for different types of hydrometrocolpos have not yet been concisely discussed. We have reviewed the literature and tried to summarize the management options applicable to most case scenarios of hydrometrocolpos.

Guidelines for genetic skeletal dysplasias for pediatricians

Skeletal dysplasia (SD) is a kind of heterogeneous genetic disorder characterized by abnormal growth, development, differentiation, and maintenance of the bone and cartilage. The patients with SD most likely to be seen by a pediatrician or orthopedic surgeon are those who present with short stature in childhood. Because each category has so many diseases, classification is important to understand SD better. In order to diagnose a SD accurately, clinical and radiographic findings should be evaluated in detail. In addition, genetic diagnosis of SD is important because there are so various SDs with complex phenotypes. To reach an exact diagnosis of SDs, cooperative approach by a clinician, a radiologist and a geneticist is important. This review aims to provide an outline of the diagnostic approach for children with disproportional short stature.

Oral manifestations of Ellis-van Creveld syndrome

Ellis-van Creveld syndrome is a rare autosomal-recessive disorder characterized by short limbs, post-axial polydactyly, ectodermal dysplasia, edentulous mandibular incisor region, absence of mucobuccal fold, congenitally missing teeth, slight serrations of the alveolar ridge and multiple small alveolar notches. The clinical report not only describes the classical oral and dental manifestations of Ellis-van Creveld syndrome but also presents unusual findings such as single-rooted and funnel-shaped primary first molars, single conical roots of primary second molars and taurodontisum, which must be considered in the differential diagnostic criteria to avoid misdiagnosis of syndromes. The article also discusses the differential diagnosis and preventive and therapeutic oral health care for these patients. The management of Ellis-van Creveld syndrome is multidisciplinary and, therefore, the oral health care provider should get updated with latest knowledge for timely referral to prevent the patient from further complications of heart defect and bony deformity.

Genetics of congenital heart diseases in syndromic and non-syndromic patients: new advances and clinical implications

Congenital heart defects (CHDs) are the most common birth defects in humans and over the last 20 years significant progress has been made in the understanding of the molecular and genetic determinants of an increasing number of CHDs. Fundamental to this progress has been the contribution of five fields of research: the epidemiological results of the Baltimore-Washington Infant Study (BWIS); the pathogenetic classification introduced by Clark; the Human Genome Project; genotype-phenotype correlation and familial recurrence studies; and transgenic animals. The recently advanced cytogenetic techniques can now detect subtle rearrangements in chromosomes, which may be overlooked by standard methods and, more recently, molecular instruments such as linkage analysis and positional cloning are being used to identify genes causing Mendelian monogenic syndromes with CHDs, such as Holt-Oram, Ellis-van Creveld and Noonan/LEOPARD syndromes. Finally, useful information is yet available with regard to genes causing isolated CHDs in individuals who do not have a genetic syndrome (an example is the mutation of NKX2.5 and GATA4 genes causing atrial septal defect). The future perspectives for the genetics of CHDs will involve three fields of interest: diagnosis; therapy; and prognosis.

Microcephaly, distinctive facies, single atrium, postaxial polydactyly, skeletal defects and mental retardation: a new familial faciocardiomelic syndrome?

Three siblings with postaxial polydactyly type A, congenital heart defect (single atrium), mental retardation, microcephaly, a distinctive facial appearance, skeletal anomalies and neonatal macrosomy were studied. Comparison with other cardiomelic syndromes previously described in the literature lead us to conclude that this is a new faciocardiomelic syndrome probably inherited as an autosomal recessive trait.

A female with complete lack of Müllerian fusion, postaxial polydactyly, and tetralogy of fallot: Genetic heterogeneity of McKusick-Kaufman syndrome or a unique syndrome?

We report a 19-year-old, non-Amish Caucasian female patient with primary amenorrhea caused by complete lack of Müllerian fusion with vaginal agenesis or Müllerian aplasia (MA), postaxial polydactyly (PAP), and tetralogy of Fallot. The genital tract anomaly of MA with and without renal or skeletal anomalies comprises Mayer-Rokitansky-Kuster-Hauser syndrome, which has not been reported with tetralogy of Fallot. The phenotypic triad of anomalies most closely resembled McKusick-Kaufman syndrome (MKS; OMIM 236700), a rare multiple congenital anomaly syndrome comprised of hydrometrocolpos (HMC), PAP, and congenital heart malformation that is inherited in an autosomal recessive pattern. While upper reproductive tract anomalies have not been reported with MKS, they have been reported with Bardet-Biedl syndrome (BBS), a syndrome that significantly overlaps with MKS. Both MKS and BBS can be caused by mutations in the MKKS or BBS6 gene on chromosome 20p12 and BBS is also associated with mutations in other genes (BBS1, BBS2, BBS4, and BBS7). To address this heterogenity, we sequenced the causative genes in MKS and BBS but no mutations in these five genes were identified. Fluorescence in situ hybridization (FISH) excluded large deletions of chromosome 20p12 and microsatellite marker studies confirmed biparental inheritance for all of the known BBS loci. The dual midline fusion defects of tetralogy of Fallot and MA suggests that either this patient has a unique syndrome with a distinct genetic etiology or that she has a genetically heterogeneous or variant form of MKS.

A genetic approach to the diagnosis of skeletal dysplasia

The skeletal dysplasias are a large and heterogeneous group of disorders. Currently, there are more than 100 recognized forms of skeletal dysplasia, which makes arriving at a specific diagnosis difficult. This process is additionally complicated by the rarity of the individual conditions. The establishment of a precise diagnosis is important for numerous reasons, including prediction of adult height, accurate recurrence risk, prenatal diagnosis in future pregnancies, and most importantly, for proper clinical treatment. When a child is referred for genetic evaluation of suspected skeletal dysplasia, clinical and radiographic indicators, and more specific biochemical and molecular tests, are used to try to arrive at the underlying diagnosis. Preferably, the clinical features and pattern of radiographic abnormalities are used to generate a differential diagnosis so that the appropriate confirmatory tests can be done. The current author will review this sequence of diagnostic steps. For geneticists, this process starts with history gathering including the prenatal and family history. This is followed by clinical examination with measurements and radiographs. Only once a limited differential diagnosis has been established, should molecular investigations be considered.

Cardiac malformations in patients with oral-facial-skeletal syndromes: clinical similarities with heterotaxia

Oral-facial-skeletal (OFS) syndromes include short rib-polydactyly (SRP) and oral-facial-digital (OFD) syndromes. Congenital heart defect (CHD), mainly atrioventricular canal defect (AVCD), is a cardinal finding in the Ellis-van Creveld (EVC) syndrome, but it occurs only occasionally in other SRP and OFD syndromes. The cardiac characteristics of all patients with OFS syndromes evaluated at our hospital from January 1986 to April 1997 were analyzed and compared with published reports. Ten patients with EVC syndrome, one with McKusick-Kaufman syndrome, and one with OFD syndrome type II had AVCD. Eight patients (67%) had a common atrium, eight (67%) a persistent left superior vena cava (LSVC) draining into the left atrium because of an unroofed coronary sinus in five (42%), and left-sided obstructive lesions in three (25%). One patient with EVC syndrome had AVCD, common atrium, double outlet right ventricle, persistent LSVC associated with "asplenia syndrome," visceral heterotaxia, and right isomerism. The combination of CHDs found in the personal series of OFS syndromes suggests pathogenetic similarity with heterotaxia syndromes. Published results also corroborate the association between OFS syndromes and CHDs usually occurring in heterotaxia. Molecular studies could shed light on the genetic mechanisms implicated in the cause of the OFS and heterotaxia syndromes.