Laparoscopic herniorrhaphy for inguinal hernia with thanatophoric dysplasia: A case report.

Thanatophoric dysplasia (TD) is a rare and severe type of skeletal dysplasia. Typical clinical findings include macrocephaly, shortening of the four limbs, underdeveloped lungs, and thoracic hypoplasia. Neonates with TD develop severe respiratory problems due to thoracic hypoplasia and require respiratory management for survival. Despite the resolution of respiratory problems, long-term survival cases are rare. Previous studies have reported that surgical procedures in patients with TD are limited to those necessary for survival, including tracheostomy, laminectomy, and ventricular shunt. A 1-year-old boy with TD was treated with laparoscopic herniorrhaphy. To the best of our knowledge, this is the first report of TD treated with laparoscopic procedure.

Chylous Ascites in an Infant with Thanatophoric Dysplasia Type I with FGFR3 Mutation Surviving Five Months.

BACKGROUND: Thanatophoric dysplasia (TD) results from sporadic de novo mutations in the FGFR3 gene. Upon confirming intrauterine diagnosis of this perinatal disease, pregnancy termination is recommended. There is limited information on the natural history of longer-term survivors with type 1 TD. CASE REPORT: A full-term neonate was confirmed via postnatal genetic testing to have type 1 TD. At 28 days, chylous ascites developed. Medium-chain triglyceride use improved the ascites. Cerebral ventriculomegaly worsened throughout life. Death due to respiratory failure occurred at age 5 months. CONCLUSION: The chylous ascites in this child with type 1 TD and survival past the neonatal stage suggests that type 1 TD may be accompanied by abnormalities of the lymphatic channels. Moreover, ventriculomegaly can be progressive.

Pathophysiological analyses of periventricular nodular heterotopia using gyrencephalic mammals.

Although periventricular nodular heterotopia (PNH) is often found in the cerebral cortex of people with thanatophoric dysplasia (TD), the pathophysiology of PNH in TD is largely unknown. This is mainly because of difficulties in obtaining brain samples of TD patients and a lack of appropriate animal models for analyzing the pathophysiology of PNH in TD. Here we investigate the pathophysiological mechanisms of PNH in the cerebral cortex of TD by utilizing a ferret TD model which we recently developed. To make TD ferrets, we electroporated fibroblast growth factor 8 (FGF8) into the cerebral cortex of ferrets. Our immunohistochemical analyses showed that PNH nodules in the cerebral cortex of TD ferrets were mostly composed of cortical neurons, including upper layer neurons and GABAergic neurons. We also found disorganizations of radial glial fibers and of the ventricular lining in the TD ferret cortex, indicating that PNH may result from defects in radial migration of cortical neurons along radial glial fibers during development. Our findings provide novel mechanistic insights into the pathogenesis of PNH in TD.

Dysmorphic choroid plexuses and hydrocephalus associated with increased nuchal translucency: early ultrasound markers of de novo thanatophoric dysplasia type II with cloverleaf skull (Kleeblattschaedel).

Prenatal diagnosis of thanatophoric dysplasia (TD) type II presenting in the first trimester with increased nuchal translucency (NT) and cloverleaf skull (Kleeblattschaedel) have been scantly reported in the medical record. Abnormal choroid plexus has been seen in association with fetal anomalies. Here we described a case of increased NT associated with indented choroid plexuses, early onset hydrocephalus and cloverleaf skull in a fetus subsequently diagnosed at early second trimester to carry a de novo mutation encoding for TD type II. The findings of dysmorphic choroid plexus, early onset hydrocephalus and cloverleaf skull at first trimester scan may be early, useful ultrasound markers of TD type II. Molecular analysis to control for possible overlapping syndromes were performed and resulted negative. Postmortem X-ray and 3D-CT scan confirmed the cloverleaf skull, narrow thorax, straight femur with rhizomelic shortening of the limbs and the presence of a communicating hydrocephalus.

Precocious appearance of the capital femoral ossific nucleus in Larsen syndrome.

BACKGROUND: Larsen syndrome is associated with multiple complications, including spinal deformities and recalcitrant joint dislocations. We noted capital femoral ossific nuclei on ultrasonographic images that were made for two infants with Larsen syndrome who were less than two weeks of age. We sought to confirm that this finding is common in patients with Larsen syndrome and unusual in patients with normal hips or idiopathic developmental dysplasia of the hip. METHODS: We identified eight patients with Larsen syndrome who had undergone ultrasonographic or radiographic evaluation of the hips before the age of three months. We compared the findings for these eight patients with those for forty consecutive patients from a prospective study of infants with developmental dysplasia of the hip who had ultrasonographic evaluation of the hips at approximately three months of age, including twenty patients who had normal clinical and ultrasonographic findings and twenty who had clinical instability of one or both hips. RESULTS: All eight patients with Larsen syndrome had radiographic or ultrasonographic evidence of an ossific nucleus at an average age of forty days (range, six to 115 days); four of these patients had evidence of an ossific nucleus at six to ten days of age. In comparison, only two of twenty normal infants (three of forty hips) and one of twenty infants (two of forty hips) with developmental dysplasia of the hip had ultrasonographic evidence of an ossific nucleus at an average age of eighty-four days (range, seventy-six to ninety-four days) (p < 0.0001, Fisher exact test). CONCLUSIONS: In this small group of patients with clinically documented Larsen syndrome, the capital femoral ossific nucleus was evident on ultrasonography of the hip as early as six days of age and was unusual in normal patients or those with idiopathic developmental dysplasia of the hip. The detection of precocious development of a capital femoral ossific nucleus in infants being screened for skeletal anomalies may warrant further evaluation for the possibility of the presence of Larsen syndrome.

High-output cardiac failure in a fetus with thanatophoric dysplasia associated with large placental chorioangioma: case report.

Placental chorioangioma is an angioma arising from chorionic tissue. Fetal thanatophoric dysplasia is a lethal skeletal dysplasia due to mutation of fibroblast growth factor receptor 3 gene. These two conditions are rare and their coexistence in a given fetus is even rarer. We present a case of a fetus with thanatophoric dysplasia having high-output cardiac failure due to a large placental chorioangioma.

FGFR3 mutation in thanatophoric dysplasia type 1 with bilateral cystic renal dysplasia: coincidence or a new association?

Thanatophoric dysplasia (TD) is a lethal dwarfism condition due to missense mutations in the fibroblast growth factor receptor 3 (FGFR3) gene. Examination of TD patients reveals mainly the involvement of the skeletal system and the brain, but also renal and cardiovascular anomalies have been described. We report the prenatal detection of TD type 1 (TD1) associated with bilateral cystic renal dysplasia (CRD) Potter's type II, in which the molecular analysis reveals the typical Arg248Cys substitution in the FGFR3 gene. CRD has not been previously described in TD or other conditions due to FGFR3 mutations, but occurs in Apert syndrome (due to FGFR2 mutations). The possible involvement of renal developmental defect in FGFR3 mutations is discussed.

The cerebral cortex malformation in thanatophoric dysplasia: neuropathology and pathogenesis.

Thanatophoric dysplasia (TD) is a relatively common, fatal form of chondrodysplastic dwarfism in which the cerebral cortex displays a unique and complex malformation. The malformation is characterized by a combination of abnormalities, which affect the temporal lobe most severely. Salient features include temporal lobe enlargement, deep transverse sulci across the inferomedial temporal surface, and hippocampal dysplasia. TD is caused by mutations of the fibroblast growth factor (FGF) receptor 3 gene (FGFR3), which result in constitutive activation of the FGFR3 tyrosine kinase. However, the link between constitutive FGFR3 activation and malformation of the cortex has been difficult to elucidate. In this review, I describe the neuropathological features of human TD, especially the cortical malformation, ascertained by examination of 45 published cases and 5 new cases, spanning gestational ages from 18 to 42 weeks. The cortical malformation is interpreted with regard to developmental mechanisms, and observations from a mouse model of TD. The evidence suggests that FGFR3 activation perturbs three key processes in cortical development: areal patterning, progenitor proliferation, and apoptosis. Defective patterning accounts for hippocampal dysplasia, while increased proliferation and decreased apoptosis account for temporal lobe hyperplasia and premature development of aberrant sulci. Disturbances in these processes may also contribute to other cortical malformations.

Prenatal diagnosis of partial agenesis of the corpus callosum in a fetus with thanatophoric dysplasia type 2.

A fetus with thanatophoric dysplasia type 2 (TD2) associated with cloverleaf skull and abnormal development of the corpus callosum is reported. This case represents the first prenatal direct visualization of a partial agenesis of the corpus callosum (ACC) using high-resolution ultrasonography and colour power Doppler, which was confirmed by post-mortem magnetic resonance imaging (MRI). The causal link between cloverleaf skull in TD and partial ACC is discussed.

Russell-Silver Syndrome in a Nigerian infant with intrauterine growth retardation.

Russell-Silver Syndrome (RSS) is a rare cause of pre-natal dwarfism, associated with recognizable dysmorphic features and limb asymmetry. The propositus was a term infant of unrelated Nigerian parents, whose 35-year-old mother had peri-conceptual haloperidol for schizophrenia. Anthropometric values suggested severe prenatal stunting in a term infant with asymmetric "head sparing" intrauterine growth retardation (IUGR). A syndromic consideration of Russell-Silver dwarfism was subsequently predicated on the distinctive dysmorphic craniofacial features of a triangular facial profile with a broad forehead and hypoplastic mandible, right upper and lower limb rhizomelia, clinodactyly of the little fingers, micro-penis, and (unilateral) cryptochidism. Routine care of a small-for-gestational-age infant was pursued, but postnatal growth remained slow (despite adequate caloric provision) until a parent-pressured discharge at 4 weeks. His subsequent demise was said to have occurred "suddenly" 2 weeks post-discharge. Despite the limitations posed by the local paucity of modern investigative tools for genetic disorders, the current case report underscores the diagnostic reality of RSS in a non-white African population. While emphasizing the need for a high index of diagnostic suspicion for congenital malformations and syndromic causes of IUGR in the African sub-region, we suspect a possible etiologic association of haloperidol embryopathy with RSS in the current case. The characteristic features, differential diagnoses, etiologic postulates/current cytogenetic and molecular genetic findings of RSS are fully reviewed in the discussion.

Schneckenbecken dysplasia, radiology, and histology.

To our knowledge this is the first report of Schneckenbecken dysplasia with the development of hydrops early in the second trimester. The radiological findings showed the typical hypoplastic iliac bones with medial extension and very flattened, on lateral view, oval-shaped vertebral bodies and short long bones. The histology showed hypercellular and hypervascular cartilage with chondrocytes with centrally located nucleus. The absence of the lacunar space as described before was also observed in some chondrocytes in our case. This male fetus was the product of consanguineous parents of Mediterranean origin compatible with autosomal recessive inheritance.

A novel skeletal dysplasia with developmental delay and acanthosis nigricans is caused by a Lys650Met mutation in the fibroblast growth factor receptor 3 gene.

We have identified a novel fibroblast growth factor receptor 3 (FGFR3) missense mutation in four unrelated individuals with skeletal dysplasia that approaches the severity observed in thanatophoric dysplasia type I (TD1). However, three of the four individuals developed extensive areas of acanthosis nigricans beginning in early childhood, suffer from severe neurological impairments, and have survived past infancy without prolonged life-support measures. The FGFR3 mutation (A1949T: Lys650Met) occurs at the nucleotide adjacent to the TD type II (TD2) mutation (A1948G: Lys650Glu) and results in a different amino acid substitution at a highly conserved codon in the kinase domain activation loop. Transient transfection studies with FGFR3 mutant constructs show that the Lys650Met mutation causes a dramatic increase in constitutive receptor kinase activity, approximately three times greater than that observed with the Lys650Glu mutation. We refer to the phenotype caused by the Lys650Met mutation as "severe achondroplasia with developmental delay and acanthosis nigricans" (SADDAN) because it differs significantly from the phenotypes of other known FGFR3 mutations.

Achondroplasia, hypochondroplasia and thanatophoric dysplasia: clinically related skeletal dysplasias that are also related at the molecular level.

This is the second of three articles on modern genetic concepts of a number of syndromes and disorders. Three short limb skeletal dysplasias with additional abnormalities of the skull are discussed. All are caused by mutations on fibroblast growth factor receptor 3 (FGFR3). A pathogenetic hypothesis is proposed to explain differences in the severity of short stature, midface deficiency, and craniosynostosis.

[Prenatal diagnosis of thanatophoric dysplasia]. / Praenatalisan kórismézett thanatophor dysplasia.

The authors report a case of a thanatophoric dysplasia associated with hydramnios diagnosed at 32 weeks' gestation by sonographic investigation. The final diagnosis was derived from radiological and hystological findings. The authors underline that the identification of a specific osteochondrodysplasia is quite difficult and postulates interdisciplinary cooperation between gynecologists, neonatologists, radiologists and pathologists. More effective counselling of affected families is the major purpose of all the efforts involved.

Neural arch stenosis and spinal cord injury in thanatophoric dysplasia.

Bony abnormalities caused by thanatophoric dysplasia affect the base of the skull and the vertebrae as well as the ribs and appendicular long bones. We present our findings in a full-term infant with thanatophoric dysplasia in whom the posterior fossa, the rostral vertebral column, and the neuraxis at and adjoining the craniovertebral junction were studied by dissection, roentgenography, and histologic examination. In this infant, malformations of the vertebral laminae, most prominent in the basiocciput and atlas vertebra, led to compression of the rostral cervical spinal cord, causing gliosis and focal necrosis. Stenosis of the foramen magnum and spinal canal may contribute to the ventilatory insufficiency that often causes death in patients with thanatophoric dysplasia. We suggest that the causes of death in patients with thanatophoric dysplasia and other severe forms of osteochondrodysplasia should be sought in neuraxial injury rather than attributed solely to pulmonary hypoplasia.