Amniotic bands in connective tissue disorders

Congenital Defects in a Patient Carrying a Novel Homozygous AEBP1 Variant: Further Expansion of the Phenotypic Spectrum of Ehlers-Danlos Syndrome Classical-like Type 2?

In 2018, a new clinical subtype, caused by biallelic variants in the AEBP1 gene, encoding the ACLP protein, was added to the current nosological classification of the Ehlers-Danlos Syndromes (EDS). This new phenotype, provisionally termed EDS classical-like type 2 (clEDS2), has not yet been fully characterized, as only nine cases have been reported to date. Here we describe a patient, homozygous for a novel AEBP1 pathogenic variant (NM_001129.5 c.2123_2124delTG (p.Val708AlafsTer5)), whose phenotype is reminiscent of classical EDS but also includes previously unreported multiple congenital malformations. Furthermore, we briefly summarize the current principal clinical manifestations of clEDS2 and the molecular evidence surrounding the role of AEBP1 in the context of extracellular matrix homeostasis and connective tissue development. Although a different coexisting etiology for the multiple congenital malformations of our patient cannot be formally excluded, the emerging role of ACLP in TGF-β and WNT pathways may explain their occurrence and the phenotypical variability of clEDS2.

Amniotic band sequence in vascular Ehlers-Danlos Syndrome (EDS): Experience of the EDS National Diagnostic Services in the UK

The association between vascular Ehlers-Danlos Syndrome (vEDS) and amniotic band sequence (ABS) has been previously reported in the literature, mostly in single patient case reports. Here, we aim to extend the current knowledge of this association through a case series of five unrelated individuals with ABS in association with molecularly confirmed vEDS, in addition to undertaking a comprehensive literature review. All the individuals were recruited through the EDS national diagnostic service in the UK following appropriate history, physical examination and genetic investigations. Clinical presentation ranged from a single constriction ring to complex craniofacial clefts to limb reduction deformities, reflecting the spectrum of ABS presentation. vEDS was inherited paternally (n = 2), maternally (n = 2) and de novo (n = 1). Previously, maternal vEDS was considered the risk factor for ABS, but our findings suggest that it may be the disease status of the fetus which poses the main risk. It is established that amniotic membrane is derived from fetal tissue, which supports our conclusions. Our observations suggest the increased risk of ABS in fetuses with vEDS. Therefore, exploring family history and features that may suggest vEDS diagnosis in patients with ABS might be useful. We also recommend that a collaborative international study would be useful to help gain a better insight into this association.

Infrequent association of two rare diseases: amniotic band syndrome and osteogenesis imperfecta

Objectives

Amniotic band syndrome and osteogenesis imperfecta are two distinct diseases that develop due to structural defects of the collagen protein. In our paper, we report the concurrence of these two diseases rarely seen in the newborn period.

Case presentation

A female infant born at 33rd gestational week was found to have constrictive bands in her right lower extremity and flexion contractures in distal joints of lower and upper extremities due to amniotic bands in postnatal physical examination. While being treated for respiratory difficulty, she was diagnosed with osteogenesis imperfecta and treated with bisphosphonates upon being found to suffer bilateral humeral fractures on the sixth day of life. She received respiratory support with mechanical ventilation due to respiratory tract complications related to osteogenesis imperfecta and died on the 384th day of life.

Conclusions

One should bear in mind that other collagen tissue diseases may accompany the amniotic band syndrome; this possibility should be definitely pursued if clinical suspicion exists.

Inherited cause of in utero digital malformations

Amniotic band sequence (ABS) is common birth defect of incompletely understood origin. Here we describe a case of ABS in a child with paternally inherited Ehlers-Danlos syndrome, vascular type (vEDS). This is the third reported instance of ABS associated with paternally inherited vEDS in the medical literature. The two main theories of ABS formation are the extrinsic and intrinsic. The extrinsic theory states that placental tears form fibrous cords that wrap around the fetus; the intrinsic states that poor vascularisation in the fetus leads to necrosis of distal extremities. We believe this case supports extrinsic theory as it shows that as an amnion weakened by vEDS in fetal components is associated with ABS.

Amniotic band sequence in paternal half-siblings with vascular Ehlers-Danlos syndrome

Familial amniotic band sequence (ABS) is rare but has been reported in the offspring of mothers with connective tissue disorders. We present a family of two half-siblings with ABS who share the same biological father. Following a serious vascular event a de novo pathogenic variant in COL3A1 was detected in the father, confirming a diagnosis of vascular Ehlers-Danlos syndrome (vEDS). The same variant was found in both his ABS-affected children but not in his unaffected child. The amniotic membrane is derived from fetal tissue, type III collagen being a component. As the affected children are paternal half-siblings, ABS was less likely due to maternal factors. Rather, the amniotic bands may have resulted from decreased type III collagen production as seen in people with vEDS, causing fragility of the amniotic membrane. Consequently, it is important to consider vEDS in patients with ABS.

Diagnosis, natural history, and management in vascular Ehlers-Danlos syndrome

Vascular Ehlers Danlos syndrome (vEDS) is an uncommon genetic disorders characterized by arterial aneurysm, dissection and rupture, bowel rupture, and rupture of the gravid uterus. The frequency is estimated as 1/50,000-1/200,000 and results from pathogenic variants in COL3A1, which encodes the chains of type III procollagen, a major protein in vessel walls and hollow organs. Initial diagnosis depends on the recognitions of clinical features, including family history. Management is complex and requires multiple specialists who can respond to and manage the major complications. A summary of recommendations for management include: Identify causative variants in COL3A1 prior to application of diagnosis, modulate life style to minimize injury, risk of vessel/organ rupture, identify and create care team, provide individual plans for emergency care ("vascular EDS passport") with diagnosis and management plan for use when traveling, centralize management at centers of excellence (experience) when feasible, maintain blood pressure in the normal range and treat hypertension aggressively, surveillance of vascular tree by doppler ultrasound, CTA (low radiation alternatives) or MRA if feasible on an annual basis. These recommendations represent a consensus of an international group of specialists with a broad aggregate experience in the care of individuals with vascular EDS that will need to be assessed on a regular basis as new information develops. © 2017 Wiley Periodicals, Inc.

Constriction Rings and Congenital Amputations of the Fingers and Toes in a Mild Case of Amniotic Band Syndrome

Amniotic band syndrome (ABS) may result in fetal anomalies that vary in severity from minor to lethal. Although numerous conditions have been grouped with this diagnosis, a subset of this population will have no other intrauterine abnormalities other than isolated defects of the extremities. ABS may present as constriction rings and congenital amputation affecting the limbs and digits. Routine sonographic evaluation of the fetus in the second trimester can identify the major defects associated with ABS. Detailed evaluation of the fetal extremities, including views of the hands and feet, will increase the detection of minor defects.

A rare combination of amniotic constriction band with osteogenesis imperfecta

Amniotic constriction bands and osteogenesis imperfecta are disorders arising from a collagen defect. We report a rare association of amniotic bands with osteogenesis imperfecta in a child. The child was born with multiple amniotic bands involving the right leg, both hands and both feet. Multiple fractures of long bones of lower limbs occurred in childhood due to trivial trauma. Deformities of the femur and tibia due to malunion with osteopenia and blue sclerae were present. The patient was treated with z plasty of constriction band of the right tibia and bisphosphonate for osteogenesis imperfecta. This rare association of both collagen diseases may provide further insight for the pathogenesis of these diseases.

ADAM "sequence" part II: hypothesis and speculation

Noted for centuries in humans, a relatively hairless mammal [e.g., Hallero, 1766; Hohl, 1828 in Klunker, 2003], the so-called amniotic deformities, adhesions, mutilations (ADAM) sequence remains causally and pathogenetically incognito. In 1930 Streeter stated " apodictically" that no evidence has been found that intra-uterine amputation is due to amniotic bands or adhesions …" and that his 16 cases provided (histological) evidence for a "germinal origin." He concluded that an amniotic cord was "not an adhesion or inflammatory product but … an anomalous developmental structure and present from the outset." In survivors the "traces" of damaged limb-buds "reveal the scars of poor germ-plasm." In 1958, Willis, in dismissing the amniotic origin of the ADAM defects (or "Streeter" or "Simonart" bands) quoted Keith [1940] to the effect that "(a)mniotic adhesions … are always produced by … the fetus – as a result of dysplasia in foetal tissues. They are the result, not the cause, of foetal malformations." Streeter [1930] mentions a potential familial case (56-year-old man and his mother), not controlled by photographs or other records and concluded "that the (ADAM) deformity is not easily transmissible," but "due to the constitution of the germ-plasm." Torpin [1968] concluded, as apodictically as Streeter and Willis, that "… proof of amnion rupture without damage to the chorionic sac is no longer "in question." Considering Torpin's decades-long study of the ADAM phenomenon and review of 494 references (missing many) it is surprising that he does not discuss the relationship between the apparent ADAM defects and other, internal anomalies that maybe present in an affected fetus or infant not evidently caused by the amniotic disruptions, adhesions or mutilations, unless his mind was made up. Our review of these internal and other presumed primary malformations in ADAM is ongoing. However, on a preliminary basis, it seems likely to us that: (1) there is an increased prevalence of such primary anomalies in the ADAM condition confirming the view and experience of others, for example Czeizel et al. [1993]; (2) these malformations (e.g., heterotaxy) may arise as early as gastrulation; (3) that, given the ADAM phenomenon is exclusively ascertained as the ADAM phenotype in fetuses and infants, that is, that its cause and ascertainment are completely congruent, then the apparent amniotic defect must also be regarded as a malformation; (4) that in such a case the ADAM phenomenon with associated primary malformation(s) is a form of syndromal pleiotropy due to one cause yet to be elucidated. To that end we recommend archiving DNA from all affected fetuses coming to autopsy and their parents and placentas and surgical tissues of all viable affected infants for ultimate exome or genome sequencing perhaps with special attention to the syncytin genes.

Acephaly: further evidence for disruption but not for amniotic bands

Complete absence of the fetal head in singleton pregnancies is a very rare defect; to our knowledge there are only 7 reported cases. Decapitation by amniotic bands has been considered as the most probable cause. However, in none of the described cases except one were amniotic bands, constriction rings, or other related findings observed, raising the possibility that mechanisms other than amputation by amniotic bands are involved. We present a further case of acephaly and discuss the role of amniotic bands and alternative mechanisms of decapitation and a possible sequence of events leading to acephaly.

Revisiting acrania: same phenotype, different aetiologies

OBJECTIVE

To evaluate the contribution of prenatal and postmortem examinations in establishing the aetiology of acrania.

METHODS

Retrospective evaluation of 14 cases of acrania managed through elective termination of pregnancy.

RESULTS

The median maternal age was 30 years (range 18-40) and median gestational age at diagnosis was 13 weeks (range 12-15). One mother had epilepsy and was taking anticonvulsants and another had uncontrolled type II diabetes mellitus. Only 3 women were using folic acid at conception. Chromosomal abnormalities were detected in 3 of 8 cases analyzed. Unilateral anopthalmia, cervical rachischisis, midline facial and limb defects coexisted with acrania in 4 cases. Acrania with craniofacial dysmorphism and asymmetrical finger amputation were observed in a case of amniotic band syndrome. A previous history of anencephaly was documented in 1 case.

CONCLUSION

Acrania is a characteristic phenotypic expression of a variety of different aetiologies. Investigation with cytogenetic studies and postmortem are essential to provide a definitive answer. This will provide a better understanding of the underlying aetiology and help establish the recurrence risk for future pregnancies.

Connective tissue and related disorders and preterm birth: clues to genes contributing to prematurity

To identify candidate genes contributing to preterm birth, we examined the existing literature on the association between known disorders of connective tissue synthesis and metabolism and related diseases and prematurity. Our hypothesis was that abnormal matrix metabolism contributes to prematurity by increasing risk of preterm premature rupture of membranes (PPROM) and cervical incompetence. Based on this review, we identified gene mutations inherited by the fetus that could predispose to preterm birth as a result of PPROM. The responsible genes include COL5A1, COL5A2, COL3A1, COL1A1, COL1A2, TNXB, PLOD1, ADAMTS2, CRTAP, LEPRE1 and ZMPSTE24. Marfan syndrome, caused by FBN1 mutations, and polymorphisms in the COL1A1 and TGFB1 genes have been associated with cervical incompetence. We speculate that an analysis of sequence variation at the loci noted above will reveal polymorphisms that may contribute to susceptibility to PPROM and cervical incompetence in the general population.

Ehlers-Danlos syndrome type IV: unusual congenital anomalies in a mother and son with a COL3A1 mutation and a normal collagen III protein profile

A mother and son with Ehlers-Danlos syndrome (EDS) type IV and unusual congenital anomalies are described. The congenital anomalies include, in the mother, amniotic band-like constrictions on one hand, a unilateral clubfoot, and macrocephaly owing to normal-pressure hydrocephaly and, in the son, an esophageal atresia and hydrocephaly. Protein analysis of collagen III in cultured fibroblasts of the mother showed no abnormalities. However, DNA analysis of the COL3A1 gene revealed a pathogenic mutation (388G-->T) in both the mother and the son. The possible relationship between the observed congenital anomalies and EDS IV are discussed. We stress that DNA analysis of COL3A1 should be performed in all patients when there is a strong suspicion of EDS IV, despite negative findings in a collagen protein analysis.

Mermaid syndrome with amniotic band disruption

An association of Amniotic Band Disruption Sequence and Mermaid Syndrome in a newborn having multiple congenital anomalies is being reported. The newborn had aberrant string like tissues attached to the amputed fingers and toes. Adhesions of amniotic bands had disrupted the fetal parts especially anteriorly in the midline, causing multiple anomalies. Apart from these features of Amniotic Band Disruption Sequence, the newborn had complete fusion of the lower limbs by cutaneous tissue, a characteristic of Mermaid Syndrome (Sirenomelia). Associated malformations were anal stenosis, rectal atresia, small horseshoe kidney, hypoplastic urinary bladder and a bicomuate uterus. The single umbilical artery had a high origin, arising directly from the aorta just distal to the celiac axis, which is unique to sirenomelia. Theories put forward regarding the etiopathogenesis of both the conditions are discussed.

Raised limb bands developing in infancy

Congenital cutaneous constriction bands are rare and often occur with other abnormalities, including the presence of rudimentary digits. This diverse syndrome lacks a precise definition and a satisfactory explanation. We describe two unusual cases with features previously undescribed, in which predominantly raised, annular limb bands became apparent postnatally. One infant was also born with foreshortened digits and a constricting limb band, suggesting a shared aetiology with other congenital cases. The development of raised bands during infancy would be difficult to reconcile with the widely held 'amniotic band hypothesis', and would be more in keeping with a multifocal developmental abnormality in limb growth.

The significance of the placenta in assessment of the newborn

The placenta may harbor many diagnostic tools available for the care of ill neonates. Such tools enable fine-tuning of diagnoses or even the establishment of diagnoses not considered during the investigation and care of the newborn. For this reason, obstetricians, pediatricians, and pathologists should all be familiar with common placental diagnoses so that sharing of the available data among these specialists may, in many cases, provide supportive and diagnostic information critical to the management of the newborn.

Amnion rupture sequence in a first trimester missed abortion

We report the diagnosis of amnion rupture sequence made by sonography and fetoscopy during the first trimester of gestation in a case of missed abortion. The investigation revealed a demised fetus with the characteristics of 9 weeks of development. The early fetus had an amnion adhesion at the tip of the nose and strands of amnion wrapped around the terminal phalanges of both feet. No defects in addition to the face and limb involvement were identified. The karyotype was normal: 46,XX. In the reported case, fetoscopy allowed confirmation of the sonographic diagnosis of an amnion rupture sequence in the first trimester of gestation and consequently helped to clarify the cause of abortion in this case of early fetal demise.

Radius hypoplasia, radial palsy, and aplasia cutis due to amniotic band syndrome

Amniotic band syndrome is one of the many causes of aplasia cutis congenita. It is usually seen as a constriction band surrounding a limb or as a membrane that adheres to some part of the body. This syndrome can be associated with various malformations. An infant with amniotic adhesions producing aplasia cutis, radial palsy, and hypoplasia of the radius is presented. Early treatment led to total functional recovery of the affected limb.

Congenital constriction band of the trunk

Constriction band of the trunk is a rare congenital malformation. A 2-year-old girl with a congenital circumferential constriction band around the waist is described. Six other cases of congenital constriction band of the trunk are reviewed. Like constriction band of the limbs, this malformation is probably related to the amniotic band syndrome. Surgical correction should be considered carefully because natural evolution is usually benign and the postoperative esthetic benefit may be questionable. There is no evidence of any risk of familial recurrence.

Ehlers-Danlos syndrome type IV caused by Gly400Glu, Gly595Cys and Gly1003Asp substitutions in collagen III: clinical features, biochemical screening, and molecular confirmation

Three patients with Ehlers-Danlos syndrome type IV (EDS IV) and biochemical evidence of structural defects in collagen III were investigated for mutations within the collagen III gene (COL3A1). Single strand conformation polymorphism analysis of alpha 1 (III) cDNA indicated the presence of different heterozygous sequence changes in each of the patients. Nucleotide sequencing revealed mutations leading to the substitution of glycine 400 with glutamic acid, glycine 595 with cysteine, and glycine 1003 with aspartic acid. EDS IV is a life-threatening disorder which, as the clinical histories of our patients and their families show, still often escapes diagnosis. Biochemical and molecular studies can clarify the diagnosis and help provide appropriate management and counselling.

Diagnostic distinction between anencephaly and amnion rupture sequence based on skeletal analysis

The axial skeletal development of eight second trimester aborted fetuses, clinically diagnosed as amnion rupture sequence with cranial involvement, was examined radiographically and histologically. Three of the eight fetuses showed axial skeletal malformation in the spine and the craniofacial skeleton corresponding to the malformations seen in anencephaly. These are vertebral body malformations, consisting of double corpora and of osseous malformations in the components of the cranial base, the corpus of the occipital bone, and the postsphenoid bone. These types of malformation, which have previously been described, are located along the original course of the notochord. The findings show that it is possible by means of radiography of the axial skeleton to distinguish between anencephalic fetuses which become secondarily involved in amnion rupture and fetuses which were initially normally developed. The method supplements detailed fetal examination and provides important information for genetic counselling.

ADAM sequence and innocent amniotic band: manifestations of early amnion rupture

Thirteen placentas with early amnion rupture (EAR) are described. These placentas were characterized by the absence of amniotic epithelium on the fetal surface, presence of a slightly fibrotic small amniotic band (remnant) attaching to the umbilical cord at the placental end, and the presence of degenerated vernix squamous cells in the fibrous stroma of chorion and amnion. Eight fetuses had ADAM sequence. Six of these fetuses were miscarried between 16 and 28 weeks of gestation. Two affected infants were born alive at gestational ages of 29 and 39 weeks. Five infants were spared by ADAM sequence; two had the umbilical cord strangulated by an amniotic band and were delivered at 27 and 37 weeks. In the 3 infants unassociated with ADAM sequence or strangulation of the umbilical cord, their placentas were interpreted as having innocent amniotic band (IAB) and they were delivered between 32 and 40 weeks. The findings in this study support Torpin's hypothesis that ADAM sequence is a complication of EAR. This ADAM sequence due to simple EAR must be separated from the limb body wall malformation complex because visceral anomalies are uncommon in the former condition but are frequently seen in the latter. In this study the placental pathology of EAR was helpful in confirming the ADAM sequence in the fetus.

Limb reduction and chorion villus sampling

Upper limb reduction was diagnosed by ultrasound scan at 17 weeks after chorion villus sampling at 9 weeks' gestation. Pregnancy was terminated and necropsy confirmed limb reduction in an otherwise normal fetus. The relationship of limb reduction to amniotic band syndrome is discussed.

Puzzling intrauterine insults

Two male infants were noted at birth to have open wounds involving a forearm. These have been associated with abnormal bone modelling and growth. The cause of these appearances remains unclear and no similar cases have been reported.

Amnion rupture sequence in previable fetuses

Amnion rupture sequence is considered an uncommon, sporadic condition among liveborn infants. We have examined 1,010 previable fetuses (9-20 weeks developmental age) to determine the incidence and nature of amnion rupture sequence at this stage of development. We found 18 affected fetuses (15 spontaneous and 3 induced abortions) with the incidence of 1:56. Eleven fetuses had limb constrictions and amputations only; 7 fetuses also had nonlimb involvement, including disruptions of the craniofacial region mimicking encephalocele, unusual facial clefts, and abdominal defects. In 6 pregnancies, constrictions of the umbilical cord by amniotic bands were the cause of fetal intrauterine death.

The amniotic band disruption complex. The pathogenesis of congenital limb ring-constrictions; an experimental study in the foetal rat

This paper reports the findings of an experimental foetal rat study which has shown that it is possible to produce mild, moderate and severe limb ring-constrictions by simulating the ligature effect of amniotic bands. Of the 40 experimental foetuses, 36 (90%) survived the in utero surgery and are included in the present study. Of these 36 foetuses, limb constriction rings were produced in 35 (97%), and an in utero limb amputation in one (3%).