Made by DATEXIS (Data Science and Text-based Information Systems) at Beuth University of Applied Sciences Berlin
Deep Learning Technology: Sebastian Arnold, Betty van Aken, Paul Grundmann, Felix A. Gers and Alexander Löser. Learning Contextualized Document Representations for Healthcare Answer Retrieval. The Web Conference 2020 (WWW'20)
Funded by The Federal Ministry for Economic Affairs and Energy; Grant: 01MD19013D, Smart-MD Project, Digital Technologies
"In utero" sonographic diagnosis is possible when characteristic features such as bilateral bowed femurs and tibia, clubbed feet, prominent curvature of the neck, a bell-shaped chest, pelvic dilation, and/or an undersized jaw are apparent
Radiographic techniques are generally used only postnatally and also rely on prototypical physical characteristics.
Genetic screening is also typically done postnatally, including PCR typing of microsatellite DNA and STS markers as well as comparative genomic hybridization (CGH) studies using DNA microarrays.
In some cases PCR and sequencing of the entire "SOX9" gene is used to diagnose CMD.
Many different translocation breakpoints and related chromosomal aberrations in patients with CMD have been identified.
The diagnosis of AOS is a clinical diagnosis based on the specific features described above. A system of major and minor criteria was proposed.
The combination of two major criteria would be sufficient for the diagnosis of AOS, while a combination of one major and one minor feature would be suggestive of AOS. Genetic testing can be performed to test for the presence of mutation in one of the known genes, but these so far only account for an estimated 50% of patients with AOS. A definitive diagnosis may therefore not be achieved in all cases.
Prenatal Diagnosis:
- Aymé, "et al." (1989) reported prenatal diagnosis of Fryns syndrome by sonography between 24 and 27 weeks.
- Manouvrier-Hanu et al. (1996) described the prenatal diagnosis of Fryns syndrome by ultrasonographic detection of diaphragmatic hernia and cystic hygroma. The diagnosis was confirmed after termination of the pregnancy. The fetus also had 2 erupted incisors; natal teeth had not been mentioned in other cases of Fryns syndrome.
Differential Diagnosis:
- McPherson et al. (1993) noted the phenotypic overlap between Fryns syndrome and the Pallister–Killian syndrome (601803), which is a dysmorphic syndrome with tissue-specific mosaicism of tetrasomy 12p.
- Veldman et al. (2002) discussed the differentiation between Fryns syndrome and Pallister–Killian syndrome, noting that differentiation is important to genetic counseling because Fryns syndrome is an autosomal recessive disorder and Pallister–Killian syndrome is usually a sporadic chromosomal aberration. However, discrimination may be difficult due to the phenotypic similarity. In fact, in some infants with 'coarse face,' acral hypoplasia, and internal anomalies, the initial diagnosis of Fryns syndrome had to be changed because mosaicism of isochromosome 12p was detected in fibroblast cultures or kidney tissue. Although congenital diaphragmatic hernia is a common finding in both syndromes, bilateral congenital diaphragmatic hernia had been reported only in patients with Fryns syndrome until the report of the patient with Pallister–Killian syndrome by Veldman et al. (2002).
- Slavotinek (2004) reviewed the phenotypes of 52 reported cases of Fryns syndrome and reevaluated the diagnostic guidelines. She concluded that congenital diaphragmatic hernia and distal limb hypoplasia are strongly suggestive of Fryns syndrome, with other diagnostically relevant findings including pulmonary hypoplasia, craniofacial dysmorphism, polyhydramnios, and orofacial clefting. Slavotinek (2004) stated that other distinctive anomalies not mentioned in previous guidelines include ventricular dilatation or hydrocephalus, agenesis of the corpus callosum, abnormalities of the aorta, dilatation of the ureters, proximal thumbs, and broad clavicles.
A clinical diagnosis of SCS can be verified by testing the TWIST1 gene (only gene in which mutations are known to cause SCS) for mutations using DNA analysis, such as sequence analysis, deletion/duplication analysis, and cytogenetics/ FISH analysis. Sequence analysis of exon 1 (TWIST1 coding region) provides a good method for detecting the frequency of mutations in the TWIST1 gene. These mutations include nonsense, missense, splice site mutation, and intragenic deletions/insertions. Deletion/duplication analysis identifies mutations in the TWIST1 gene that are not readily detected by sequence analysis. Common methods include PCR, multiplex ligation-dependent probe amplification (MLPA), and chromosomal microarray (CMA). Cytogenetic/FISH analysis attaches fluorescently labels DNA markers to a denatured chromosome and is then examined under fluorescent lighting, which reveals mutations caused by translocations or inversions involving 7p21. Occasionally, individuals with SCS have a chromosome translocation, inversion, or ring chromosome 7 involving 7p21 resulting in atypical findings, such as, increased developmental delay. Individuals with SCS, typically have normal brain functioning and rarely have mental impairments. For this reason, if an individual has both SCS and mental retardation, then they should have their TWIST1 gene screened more carefully because this is not a normal trait of SCS. Cytogenetic testing and direct gene testing can also be used to study gene/chromosome defects. Cytogenetic testing is the study of chromosomes to detect gains or losses of chromosomes or chromosome segments using fluorescent in situ hybridization (FISH) and/or comparative genomic hybridization (CGH). Direct gene testing uses blood, hair, skin, amniotic fluid, or other tissues in order to find genetic disorders. Direct gene testing can determine whether an individual has SCS by testing the individual's blood for mutations in the TWIST1 gene.
Up until recently, experts frequently disagreed on whether a patient had SCS, Crouzon syndrome, isolated craniosynostosis, or some other disease because the symptoms are so closely related, they literally had no way of differentiating between all of them. However, we now have direct gene testing, which allows for a more definitive diagnosis because it allows them to be differentiated from each other based on which gene is mutated in each condition. The following is a list of conditions commonly confused/misdiagnosed for SCS, some of their symptoms, and which mutated gene each contains:
Carrier testing for Roberts syndrome requires prior identification of the disease-causing mutation in the family. Carriers for the disorder are heterozygotes due to the autosomal recessive nature of the disease. Carriers are also not at risk for contracting Roberts syndrome themselves. A prenatal diagnosis of Roberts syndrome requires an ultrasound examination paired with cytogenetic testing or prior identification of the disease-causing ESCO2 mutations in the family.
Amniotic band syndrome is considered an accidental event and it does not appear to be genetic or hereditary, so the likelihood of it occurring in another pregnancy is remote. The cause of amnion tearing is unknown and as such there are no known preventative measures.
Amniotic band syndrome is often difficult to detect before birth as the individual strands are small and hard to see on ultrasound. Often the bands are detected indirectly because of the constrictions and swelling upon limbs, digits, etc. Misdiagnosis is also common, so if there are any signs of amniotic bands, further detailed ultrasound tests should be done to assess the severity. 3D ultrasound and MRI can be used for more detailed and accurate diagnosis of bands and the resulting damage/danger to the fetus.
The overall prognosis is excellent in most cases. Most children with Adams–Oliver syndrome can likely expect to have a normal life span. However, individuals with more severe scalp and cranial defects may experience complications such as hemorrhage and meningitis, leading to long-term disability.
Patients with abnormal cardiac and kidney function may be more at risk for hemolytic uremic syndrome
The symptoms would appear at birth or shortly after birth. The combination of physical symptoms on the child would suggest they have CHILD syndrome. A skin sample examined under a microscope would suggest the characteristics of the syndrome and an X-Ray of the trunk, arms, and legs would help to detect underdeveloped bones. A CT scan would help detect problems of the internal organs.
For most cases the diagnosis for congenital amputation is not made until the infant is born. One procedure that is helpful in determining this condition in an infant is an ultrasound examination of a fetus when still in the mother's abdomen as it can reveal the absence of a limb. However, since ultrasounds are routine they may not pick up all the signs of some of the more subtle birth defects.
The most popular method of treatment for congenital amputation is having the child be fit for a prosthesis which can lead to normal development, so the muscles don't atrophy. If there is congenital amputation of the fingers, plastic surgery can be performed by using the big toe or second toes in place of the missing fingers of the hand.
In rare cases of amniotic banding syndrome, if diagnosed "in utero", fetal surgery may be considered to save a limb which is in danger of amputation.
Cytogenetic preparations that have been stained by either Giemsa or C-banding techniques will show two characteristic chromosomal abnormalities. The first chromosomal abnormality is called premature centromere separation (PCS) and is the most likely pathogenic mechanism for Roberts syndrome. Chromosomes that have PCS will have their centromeres separate during metaphase rather than anaphase (one phase earlier than normal chromosomes). The second chromosomal abnormality is called heterochromatin repulsion (HR). Chromosomes that have HR experience separation of the heterochromatic regions during metaphase. Chromosomes with these two abnormalities will display a "railroad track" appearance because of the absence of primary constriction and repulsion at the heterochromatic regions. The heterochromatic regions are the areas near the centromeres and nucleolar organizers. Carrier status cannot be determined by cytogenetic testing. Other common findings of cytogenetic testing on Roberts syndrome patients are listed below.
- Aneuploidy- the occurrence of one or more extra or missing chromosomes
- Micronucleation- nucleus is smaller than normal
- Multilobulated Nuclei- the nucleus has more than one lobe
Studies suggest that prenatal care for mothers during their pregnancies can prevent congenital amputation. Knowing environmental and genetic risks is also important. Heavy exposure to chemicals, smoking, alcohol, poor diet, or engaging in any other teratogenic activities while pregnant can increase the risk of having a child born with a congenital amputation. Folic acid is a multivitamin that has been found to reduce birth defects.
In France, Aymé, "et al." (1989) estimated the prevalence of Fryns syndrome to be 0.7 per 10,000 births based on the diagnosis of 6 cases in a series of 112,276 consecutive births (live births and perinatal deaths).
Surgical correction is recommended when a constriction ring results in a limb contour deformity, with or without lymphedema.
Diagnosis is based on physical examination including radiographs of the hands and feet and imaging studies of the kidneys, bladder, and female reproductive tract. HOXA13 is the only gene known to be associated with HFGS. Approximately 60% of mutations are polyalanine expansions. Molecular genetic testing is clinically available.
Diagnosis depends on the clinical scenario. However, karyotyping is an essential test for diagnosis.
Tetra-amelia syndrome has been reported in only a few families worldwide.
According to a 2011 study by Bermejo-Sanchez, amelia – that is, the lacking of one or more limbs – occurs in roughly 1 out of every 71,000 pregnancies.
Surgical treatment of the cleft hand is based on several indications:
Improving function
- Absent thumb
- Deforming syndactyly (mostly between digits of unequal length like index and thumb)
- Transverse bones (this will progress the deformity; growth of these bones will widen the cleft)
- Narrowed first webspace
- The feet
Aesthetical aspects
- Reducing deformity
The timing of surgical interventions is debatable. Parents have to decide about their child in a very vulnerable time of their parenthood. Indications for early treatment are progressive deformities, such as syndactyly between index and thumb or transverse bones between the digital rays. Other surgical interventions are less urgent and can wait for 1 or 2 years.
The incidence of VACTERL association is estimated to be approximately 1 in 10,000 to 1 in 40,000 live-born infants. It is seen more frequently in infants born to diabetic mothers. While most cases are sporadic, there are clearly families who present with multiple involved members.
There is currently no treatment for CHILD syndrome so any treatment would target the symptoms currently present. Emoillents like Lac-Hydran (ammonium lactate) and Ureaphil (urea) are used to treat scaly patches on the skin. A pediatric orthopedic surgeon can evaluate any underdevelopment in the bones and treat them if necessary.
There is a compound that is a topical liquid that can calm lesions down on older adults and make them go away on younger children. The mixture was made by Dr. Amy Paller at Children's Hospital. It is mixed as follows: to make 250 ml: Grind up lovastatin tablets 5g (10-20-40-80 mg); mix with cholesterol NF powder (NDC# 51927-1203-00, PCCA) 5g; mix with preserved water while mixing (eventually mixing for 1/2 hour with electronic mortar and pestle) to bring to full volume with preserved water. 8 oz
Additional findings that may be present in HFGS according to the latest research are:
- Limited metacarpophalangeal flexion of the thumb or limited ability to oppose the thumb and fifth finger
- Hypoplastic thenar eminences
- Medial deviation of the great toe (hallux varus), a useful diagnostic sign when present
- Small great toenail
- Fifth-finger clinodactyly, secondary to a shortened middle phalanx
- Short feet
- Altered dermatoglyphics of the hands; when present, primarily involving distal placement of the axial triradius, lack of thenar or hypothenar patterning, low arches on the thumbs, thin ulnar loops (deficiency of radial loops and whorls), and a greatly reduced ridge count on the fingers
Radiographic findings
- Hypoplasia of the distal phalanx and first metacarpal of the thumbs and great toes
- Pointed distal phalanges of the thumb
- Lack of normal tufting of the distal phalanges of the great toes
- Fusions of the cuneiform to other tarsal bones or trapezium-scaphoid fusion of the carpals
- Short calcaneus
- Occasional bony fusions of the middle and distal phalanges of the second, third, fourth, or fifth toes
- Delayed carpal or tarsal maturation
- Metacarpophalangeal profile reflecting shortening of the first metacarpal, the first and second phalanges, and the second phalanx of the second and fifth digits
Urogenital Defects
Females may have the following:
- Vesicoureteral reflux secondary to ureteric incompetence
- Ectopic ureteral orifices
- Trigonal hypoplasia
- Hypospadiac urethra
- Subsymphyseal epispadias
- Patulous urethra
- Urinary incontinence (related to structural anomalies and weakness of the bladder sphincter muscle)
- Small hymenal opening
- Various degrees of incomplete Müllerian fusion with or without two cervices or a longitudinal vaginal septum
Males may have the following:
- Retrograde ejaculation (related to structural anomalies and weakness of the bladder sphincter muscle)