Biomedical subjects

John M Opitz

Publications and source records attributed to John M Opitz.

At least 37 records · Page 2Linked to original sources

PubMed2004

Mental retardation, Robin sequence, and brachydactyly: further confirmation of a new syndrome.

Recently we reported two sibs, brother and sister, with a new multiple congenital anomalies/mental retardation (MCA/MR) syndrome characterized by mild to moderate psychomotor delay, Robin sequence, distinctive facial appearance, and brachydactyly. We have subsequently observed a similar pattern of anomalies in two unrelated patients who also showed additional clinical findings. This new observation supports the existence of a new syndrome and expands the phenotypic spectrum of the condition.

Abnormalities, Multiple↗

PubMed2004

Goethe's bone and the beginnings of morphology.

Biology as a discipline per se and its agenda, seems not to have been burdened from its beginnings as heavily with neo-Platonism as its subspecialty morphology, conceptualized at the same time by Goethe and Burdach. One of the reasons may have been that biologists were then regarded as "mere" naturalists, "doing" anatomy and embryology, breeding, and field work (as did Darwin, Wallace, Bateson and a legion of others during the 19th century), whereas the, perhaps more elitist, morphologists, ab initio devoted themselves to the origin, even to the Kantian analysis of causes of development and its variability within and between species. Since Goethe included abnormal plant development in his studies, his definition of morphology as the science of the form, formation and transformation of living organisms may be modified to include the concept of malformation, although the embryological and comparative analysis of vertebrate/mammalian malformation had its real inception somewhat later with the younger Meckel. In view of the meaning attached by his French contemporaries to the term transformisme (eventually defined as evolution) one would err considering Goethe as a prophet of "descent;" he was not, referring primarily to the continuous state of flux of living beings. Nonetheless, Goethe and Burdach independently coined the concept of morphology and set its agenda, increasingly freed of Naturphilosophie, an agenda that dominated 19th century biology but which did not come to fruition in its causal analysis of form and its formation until the 20th century, after Mendel, Darwin and the pioneers of experimental embryology (a.o., Roux, Driesch, Spemann, Vogt). In his discovery of the intermaxillary bone in humans (Goethe's bone), he had a startling insight, against conventional wisdom, into the anatomical, hence developmental, similarity of primate/mammals. During his lifetime, this was still called analogie by his great French contemporary Etienne Geoffroy St-Hilaire who actually meant what Owen later called homology which became one of Darwin's most powerful arguments for descent. A case of a pearl found by a blind chicken? Definitely not; Goethe had his nose far too close to the ground to have missed any of the major intellectual trends in the "life-sciences" in the late 18th/early 19th century; but, he was too much of an amateur to have had the kind of insights of grand plans granted to von Baer, Mendel and Darwin.

Anatomy↗

PubMed2004

A double cryptic chromosome imbalance is an important factor to explain phenotypic variability in Wolf-Hirschhorn syndrome.

A total of five Wolf-Hirschhorn syndrome (WHS) patient with a 4p16.3 de novo microdeletion was referred because of genotype-phenotype inconsistencies, first explained as phenotypic variability of the WHS. The actual deletion size was found to be about 12 Mb in three patients, 5 Mb in another one and 20 Mb in the last one, leading us to hypothesize the presence of an extrachromosome segment on the deleted 4p. A der(4)(4qter --> p16.1::8p23 --> pter) chromosome, resulting from an unbalanced de novo translocation was, in fact, detected in four patients and a der(4)(4qter --> q32::4p15.3 --> qter) in the last. Unbalanced t(4;8) translocations were maternal in origin, the rec(4p;4q) was paternal. With the purpose of verifying frequency and specificity of this phenomenon, we investigated yet another group of 20 WHS patients with de novo large deletions (n = 13) or microdeletions (n = 7) and with apparently straightforward genotype-phenotype correlations. The rearrangement was paternal in origin, and occurred as a single anomaly in 19 out of 20 patients. In the remaining patient, the deleted chromosome 4 was maternally derived and consisted of a der(4)(4qter --> 4p16.3::8p23 --> 8pter). In conclusions, we observed that 20% (5/25) of de novo WHS-associated rearrangements were maternal in origin and 80% (20/25) were paternal. All the maternally derived rearrangements were de novo unbalanced t(4;8) translocations and showed specific clinical phenotypes. Paternally derived rearrangements were usually isolated deletions. It can be inferred that a double, cryptic chromosome imbalance is an important factor for phenotypic variability in WHS. It acts either by masking the actual deletion size or by doubling a quantitative change of the genome.

Abnormalities, Multiple↗

PubMed2003

Conjoined twins: morphogenesis of the heart and a review.

Five cases of conjoined twins have been studied. These included three thoracopagus twins, one monocephalus diprosopus (prosop = face), and one dicephalus dipus dibrachus. The thoracopagus twins were conjoined only from the upper thorax to the umbilicus with a normal foregut. These three cases shared a single complex multiventricular heart, one with a four chambered heart with one atrium and one ventricle belonging to each twin with complex venous and arterial connection; two had a seven chambered heart with four atria and three ventricles. The mono-cephalus diprosopus twins had a single heart with tetralogy of Fallot. The dicephalus twins had two separate axial skeletons to the sacrum, two separate hearts were connected between the right atria with a shared inferior vena cava. Thoracopagus twinning is associated with complex cardiac malformations. The cardiac anlagen in cephalopagus or diprosopus are diverted and divided along with the entire rostral end of the embryonic disc and result in two relatively normal shared hearts. However, in thoracopagus twins the single heart is multiventricular and suggests very early union with fusion of the cardiac anlagen before significant differentiation. Cardiac morphogenesis in conjoined twins therefore appears to depend on the site of the conjoined fusion and the temporal and spatial influence that determines morphogenesis as well as abnormally oriented embryonic axes.

Adolescent↗

PubMed2003

Splenogonadal fusion-limb defect "syndrome" and associated malformations.

Two types of splenogonadal fusion (SGF) have been proposed. In the continuous type the spleen is connected to the gonad, and often it is associated with limb defects and other anomalies such as micrognathia, microglossia, anal atresia, and hypoplastic lungs. Associated abnormalities are lower in the discontinuous type of SGF, where there is fusion between the gonad and accessory splenic tissue, without connection with the normal spleen. The cause of SGF and SGF with limb defects (SGFLD) is unknown. On the basis of associated orofacial limb abnormalities, some authors have suggested that SGFLD may be related to the Hanhart complex. Others have noted the overlap between SGFLD and femoral-facial syndrome (FFS). We consider SGFLD a developmental field defect that originates during blastogenesis. Although the cause is unknown, the earlier its action, the more severe the involvement resulting in SGFLD; later action may result only in SGF.

Abnormalities, Multiple↗

PubMed2003

Sirenomelia sequence according to the distance between the first sacral vertebra and the ilia.

The development of the iliac bones and lower limbs are parallel processes depending on the normal ontogeny of the caudal blastema [O'Rahilly and Müller, 1989; Opitz, 1993; Opitz et al., 2000]. We hypothesized that the pathogenetic mechanisms leading to fused lower limbs would in parallel displace the ilia caudally and medially and that the degree of this displacement might correlate with the severity of the iliac and lower limb defects. Thus the purpose of the study was to test this hypothesis in a sample of 12 sirenomelic fetuses. The fetuses GA 16-39 weeks, spontaneously or therapeutically aborted, were radiographed in the frontal projection as part of a requested autopsy. From each radiograph, a line was drawn connecting the most cranial part or the two ilia. After that the distance was measured vertically between this line and the most cranial part of the first sacral vertebral body (iliac-sacral distance (ISD)). A second distance was measured horizontally between the most lateral part of the two iliae (bi-iliac distance (BD)). As a result, ISD correlates with the iliac/femur phenotype. Separate ilia and femora occur only in cases with normal ISD. Fused ilia or femora or both are seen only in fetuses with mildly increased ISD, whereas a single iliac bone and femur occur only in cases with greatly increased ISD. The increase of the ISD does not correlate with the severity of more distal limb involvement. There was a correlation between the ISD and the BD values; the higher the ISD, the shorter the BD. Based on these findings, we propose an extended classification of Sirenomelia to be tested by other researchers.

Ectromelia↗

PubMed2003

Fetus-in-fetu form of monozygotic twinning with retroperitoneal teratoma.

One of the commonest defects of blastogenesis is monozygotic twinning resulting in separate or conjoint twins, the latter including a category of internal, "endoparasitic," or fetus-in-fetu twins. We report the third known instance of endoparasitic twinning associated with a benign teratoma at age 1. The host, twin, and teratoma were monozygotic by DNA analysis.

Female↗

PubMed2003

CFC syndrome.

Explore the source record for details and available documents.

Abnormalities, Multiple↗

PubMed2003

Apparent encephalocele in twin fetus papyraceus with twin-reversal arterial perfusion.

An apparently iniencephalic or exencephalic monoamniotic monochorionic female twin fetus, delivered as a fetus papyraceus at 28 weeks of gestation, had severe anomalies of the central nervous system and spine, including occipital encephalocele with a defect of the occipital bone. The encephalocele contained a spherical mass of autolyzed brain tissue without identifiable cerebellum or vermis. The cervical canal was widely patent dorsally, there were severe bony anomalies, including agenesis and fusion of vertebrae in the cervicothoracic spine. The upper limbs were absent. All organs were hypoplastic and autolyzed. The hypoplastic heart had three chambers. The placenta was monochorionic and monoamniotic; barium injection showed a twin-reversal arterial perfusion and entanglement of the umbilical cords.

Abnormalities, Multiple↗

PubMed2003

Documentation of anomalies not previously described in Fryns syndrome.

We report on a case of Fryns syndrome with microcephaly, multiple facial anomalies, hypoplasia of distal phalanges, diaphragmatic defect with a thin, translucent diaphragm, microphthalmia (right), anophthalmia (left), and multiple midline developmental defects including gastroschisis, central nervous system defects including left arrhinencephaly and cerebellar hypoplasia, midline cleft of the upper lip, alveolar ridge and maxillary bone, and cleft nose with bilateral choanal atresia. These defects add to our knowledge of the phenotype of Fryns syndrome.

Abnormalities, Multiple↗

PubMed2003

Specific congenital heart defects in RSH/Smith-Lemli-Opitz syndrome: postulated involvement of the sonic hedgehog pathway in syndromes with postaxial polydactyly or heterotaxia.

BACKGROUND: RSH/Smith-Lemli-Opitz syndrome is an autosomal recessive syndrome due to an inborn error of cholesterol metabolism and is characterized by developmental delay, facial anomalies, hypospadias, congenital heart defect (CHD), postaxial polydactyly, and 2-3 toe syndactyly. CHD is found in half of the propositi, and a specific association with atrioventricular canal defect (AVCD) and anomalous pulmonary venous return has been demonstrated. METHODS: We report on an additional patient with RSH/SLOS presenting with complete AVCD and anomalous pulmonary venous return, and discuss the possible relationship of the Sonic Hedgehog (SHH) pathway as causative factor of these CHDs and those in heterotaxia patients with postaxial polydactyly syndromes. RESULTS: Anatomic similarities between heterotaxia and CHDs of several syndromes with postaxial polydactyly have been noted previously, considering the frequent association of AVCD with common atrium in these conditions. It is known that both CHDs of heterotaxia and postaxial polydactyly can be related to abnormalities of the SHH pathway. Cholesterol has a critical role in the formation of normally active hedgehog proteins. It could be hypothesized that specific types of CHDs in RSH/SLOS can be caused by modifications of the SHH protein related to the defect of cholesterol biosynthesis. CONCLUSIONS: The specific association of AVCD and anomalous pulmonary venous return in patients with RSH/SLOS and the finding of AVCD +/- common atrium in several syndromes with polydactyly leads to the hypothesis that heterotaxia due to SHH anomalies could be involved in a large spectrum of conditions. Perturbations in different components of the SHH pathway could lead to several developmental errors presenting with partially overlapping clinical manifestations.

Consanguinity↗

PubMed2003

Craniocervical anomalies in Dubowitz syndrome. Three cases and a literature review.

Dubowitz syndrome is a disorder involving craniofacial abnormalities, growth retardation and mental retardation. Approximately 142 cases have been reported, with various associated other anomalies. These include cardiovascular, urogenital and endocrine abnormalities, as well as a predisposition to infections and hematological malignancies. Scoliosis has been described in association with this syndrome, as have isolated vertebral abnormalities. There has, however, been no description of craniocervical abnormalities. We describe three Dubowitz patients with significant craniocervical abnormalities.

Adult↗

PubMed2002

Defects of blastogenesis.

Ever more frequent and closer involvement by clinical geneticists and counselors in the prenatal assessment of development mandates a better understanding of all stages of human ontogeny, but especially those of earliest development during which most of the lethal and all of the gross, multiple and complex defects of morphogenesis arise. Because of the phenomenon of universality, i.e., identical molecular inductive mechanisms involved in the process of embryonic pattern formation in all vertebrates, experimental animals indeed are a most valuable approach to an understanding of the causal and formal aspects of development and are beginning to forge essential, strong bonds between molecular biologists and clinicians in a mutually supportive discipline of developmental biology. However, to grieving parents of a stillborn fetus with, say, Pentalogy of Cantrell, sirenomelia or otocephaly, mouse data offer little comfort or reassurance about recurrence; thus, it is imperative to make ever more effective a science of human teratology (sensu lato) with participating reproductive geneticists, obstetricians, neonatologists, ultrasonographers, pediatric/fetal pathologists, cytogeneticists and pediatric geneticists to generate the diagnostic, pathogenetic and causal data necessary to counsel and to comfort the parents. Few molecular data exist on causes of blastogenetic defects in humans; however, the phenomenon of parsimony, whereby the same "morphogenetic" molecule, say, sonic hedgehog (SHH), is "deployed" simultaneously or sequentially during the morphogenesis (and even the histogenesis) of several/many embryonic primordia, makes it likely that a genetic/epigenetic disturbance of such an inductive system will have multiple effects on blastogenetic, organogenetic and perhaps also histogenetic events in the embryo. If causally defined, such a pattern of anomalies constitutes pleiotropy, and the embryo/fetus can be said to have a syndrome. If cause is unknown, the presumption of pleiotropy is less certain, and the fetus/infant may be said to have an "association" with low empiric recurrence risk.

Blastocyst↗

PubMed2002

FG syndrome: linkage analysis in two families supporting a new gene localization at Xp22.3 [FGS3].

FG syndrome (OMIM 305450) is an X-linked condition comprising mental retardation, congenital hypotonia, constipation or anal malformations, and a distinctive appearance with disproportionately large head, tall and broad forehead, cowlicks and telecanthus. In a first linkage analysis carried out on 10 families, we demonstrated heterogeneity and assigned one gene [FGS1] to region Xq12-q21.31 [Briault et al., 1997: Am J Med Genet 73:87-90] corroborated by Graham et al. [1998: Am J Med Genet 80:145-156]. Heterogeneity was supported by the study of one family with apparent FG syndrome co-segregating with an inversion of X chromosome [inv(X)(q11q28)] ([FGS2], OMIM 300321) [Briault et al., 1999: Am J Med Genet 86:112-114 and Briault et al., 2000: Am J Med Genet 95:178-181]. We present the results of a new linkage analysis carried out on two families with FG syndrome. The two earlier known loci for FG syndrome, FGS1 and FGS2 (Xq11 or Xq28) were excluded by multipoint analysis of both families. Linkage was found, however, with locus DXS1060 suggesting that a third FG locus might be located at Xp22.3. In this region, two potential candidate genes, VCX-A and PRKX, were excluded by sequence analysis of the coding region in patients of the two reported FG families. The search for new candidate genes is in progress.

Abnormalities, Multiple↗

PubMed2002

HOXD13 polyalanine tract expansion in classical synpolydactyly type Vordingborg.

In 1927, Oluf Thomsen, in a classic paper, described a seven-generation family with autosomal dominant axial synpolydactyly (SPD)--the Vordingborgtyp of axis duplication and dysostosis. Expansion of a polyalanine tract in the HOXD13 gene is known to cause synpolydactyly. We have rediscovered part of the family described by Thomsen, and detected a 9 triplet polyalanine expansion within HOXD13segregating with the disorder. The phenotypic spectrum in mutation carriers ranged from severe to inapparent bone malformations. In the latter case, only dermatoglyphics revealed the genetic status.

Alanine↗

PubMedDate not supplied

Cholesterol and development: the RSH ("Smith-Lemli-Opitz") syndrome and related conditions.

The half-century of lipophobia in the United States may be abating with some return of sanity on the discussion of health and dietary fat [Taubes, 2001]. The youngest victims of this collective, decades long madness are those infants deprived for one reason or another of breast milk. They are unable to speak for themselves at a time of greatest need for cholesterol during growth, the most critical period of myelination of central and peripheral nervous system, formation of bone and bile, and of every steroid hormone. Some of the commercial formulas they are fed contain only 1 or 2 mg of cholesterol per 100 g edible portion contrasted with almost 14 mg in breast milk. One can only hope that the confidence in their endogenous ability to synthesize sufficient amounts of cholesterol is not misplaced. Pediatric pathology has learned that when this endogenous ability fails during embryogenesis on the basis of mutations in the postsqualene biosynthesis of cholesterol, a startling variety of developmental pathology may present itself ranging from lethal forms of "idiopathic" hydrops, microcephaly with cerebral dysgenesis and dysmyelinization, agenesis of corpus callosum, cerebellar vermis dysgenesis, cataracts, cleft palate, many different forms of congenital heart defect, pyloric stenosis and/or Hirschsprung dysganglionosis, adrenal (cortical) insufficiency, cholestatic liver disease, limb malformations, and genital ambiguity in genetic males. Population genetic considerations suggest a hypothetical birth prevalence of the RSH (so-called Smith-Lemli-Opitz) syndrome, the commonest of these Garrodian errors of cholesterol biosynthesis, of 1/2500; since only about 1/15,000 to 1/20,000 homozygotes are liveborn and biochemically confirmed, over 80% prenatal or perinatal mortality must occur and deserves the most discerning of services from birth attendants, perinatologists, neonatologists, and fetal/pediatric pathologists. An easy, reliable, economical biochemical test for the presence of 7-dehydrocholesterol is available and the commonest mutation, the IVS8-1G-->C mutation, is quickly and reliably tested for molecularly. Thus, the successful diagnosis, even after death, will contribute substantially to correct genetic counseling, carrier detection, prenatal diagnosis, and treatment in those known to be affected prenatally andplanned to be liveborn. Thus, developmental pathology plays an integral, vital role in preventive medicine.

Abortion, Spontaneous↗

PubMedDate not supplied

Probable second fetus with Marles-Chudley syndrome: cardiac calcifications with ulnar deficiency and absent/hypoplastic thumbs.

In 1990 Marles and Chudley reported on an infant with absent ulnae and concomitant radial hypoplasia, oligodactyly, hydropsfetalis, and apparent endocardial fibroelastosis (EFE) and, on the basis of phenotype and parental consanguinity, postulated autosomal recessive inheritance. Recently we were privileged to study parts of a fetus who had presented at ultrasonography with cardiac calcifications, micrognathia, and severe ulnar dysgenesis. The small pieces of heart we received showed neither endocardial fibroelastosis nor calcifications. Thus, we had initial doubts that we were dealing with the Marles-Chudley syndrome. However, a review by Chudley of the heart findings in his cases did show the calcifications usually seen in primary or secondary EFE. The parents of Dr. Chudley's patient were Flipino; the father of our patient was a Samoan. This suggests that there exists a gene for autosomal recessive Marles-Chudley syndrome in the Poynesian population with pleiotropic effects on upper limb development and cardiac histogenesis.

Abnormalities, Multiple↗

PubMedDate not supplied

Prenatal death in Fraser syndrome.

Cryptophthalmos may be partial or complete, unilateral or bilateral, apparently nonsyndromal or syndromal. A recent study of 2 stillborn infants at the University of Utah prompted an analysis of the developmental aspects of the syndromal form (Fraser syndrome). We conclude that, per se, cryptophthalmos is a developmental field defect on the basis of heterogeneity (autosomal dominant and recessive forms) and phylogeneity (occurrence also in the pheasant, rabbit, pigeon, dog, and mouse). In humans this autosomal recessive disorder maps to 4q21, is homologous to the bleb (bl/bl) mouse, and is due to mutations in the FRAS1 gene that codes for a 4007 amino acid protein 85% identical to the Fras1 gene of the bleb mouse. Commonest anomalies in humans are cryptophthalmos, cutaneous syndactyly of digits, abnormal ears and genitalia, renal agenesis, and congenital heart defects. Almost half of affected infants are stillborn or die in infancy, and mental retardation is common. The pathogenesis evidently involves abnormal epithelial integrity during prenatal life. Older (mostly German) publications, some dating to the 19th century, provide a fascinating historical insight into the process of syndrome delineation.

Abnormalities, Multiple↗