Craniosynostosis Following Fetal Methotrexate Exposure.

Methotrexate (MTX) is an antimetabolite, folic acid antagonist that inhibits purine nucleotide production, DNA synthesis, and cellular proliferation. Despite widespread therapeutic uses, MTX remains a potent teratogen. Methotrexate embryopathy encompasses multiorgan system dysfunction, including intrauterine growth restriction as well as cardiac, craniofacial, renal, genital, and skeletal abnormalities. Effects of MTX exposure on fetal development continue to be described. This series of 4 patients with MTX-associated craniosynostosis represents the largest published association between prenatal MTX exposure and premature cranial suture closure.

Recombinant human bone morphogenetic protein-2-induced craniosynostosis and growth restriction in the immature skeleton.

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) delivered on an absorbable collagen sponge is a U.S. Food and Drug Administration-approved therapy effective at generating bone formation. In pediatric patients for whom other therapeutic options have been exhausted, rhBMP-2 is used off-label to address problematic bony defects. In the skeletally immature patient, the safety of rhBMP-2 therapy remains uncertain. Experiments are needed that investigate the effect of rhBMP-2 on growth and development in clinically relevant models. METHODS: Ten juvenile rabbits underwent creation of a parietal skull defect that was treated with either 0.2 mg/cc rhBMP-2/absorbable collagen sponge or a neutral buffer solution/absorbable collagen sponge. Amalgam markers were placed at suture confluences to track suture separation and skull growth. Cranial growth was assessed radiographically at 10, 25, 42, and 84 days of age. Means and standard deviations for the various craniofacial growth variables were calculated and compared. Mean differences were considered significant for values of p < 0.05. At 84 days, sutures were analyzed by means of micro-computed tomographic scanning and histologic staining. RESULTS: Treatment with rhBMP-2 resulted in fusion of the coronal sutures bilaterally, with variable fusion of the sagittal suture by cephalometric, radiographic, and histologic analysis. There were statistically significant changes to coronal suture growth, sagittal suture growth, skull height, craniofacial length, and intracranial volume (p < 0.05). CONCLUSIONS: The use of rhBMP-2 in this juvenile animal model resulted in skeletal changes that may be undesirable in a clinical setting. The appearance of these fused sutures suggested a direct effect of rhBMP-2. Further work is required to limit the effect of rhBMP-2 to the target defect when used in the immature skeleton.

Induced premaxillary suture fusion: class III malocclusion model.

The etiology of class III malocclusion remains unknown. The present study investigates the relationship between craniofacial morphology and premaxillary suture fusion to test the hypothesis that class III malocclusion may be related to premaxillary suture fusion. Cyanoacrylate was applied to immobilize the left premaxillary suture in the experimental group. Sham surgeries in rats were used for controls. Dental impressions and radiographs were taken before and after surgery for comparison of craniofacial differences between groups. Overall cranial base lengths, craniofacial widths, and craniofacial angulations related to the anterior base showed significant differences between groups. At the end of the experiment, the growth of the snout in the experimental group was inhibited and deviated to the treated side, while no obvious change was seen in the control group. The results show that induced premaxillary suture fusion can affect craniofacial morphology and indicate that premature premaxillary suture fusion may result in class III malocclusion.

Noggin inhibits postoperative resynostosis in craniosynostotic rabbits.

UNLABELLED: Inhibition of bone formation after surgery to correct craniosynostosis would alleviate the need for secondary surgeries and decrease morbidity and mortality. This study used a single dose of Noggin protein to prevent resynostosis and improve postoperative outcomes in a rabbit model of craniosynostosis. INTRODUCTION: Craniosynostosis is defined as the premature fusion of one or more of the cranial sutures, which causes secondary deformations of the cranial vault, cranial base, and brain. Current surgical intervention involves extirpation of the fused suture to allow unrestricted brain growth. However, resynostosis of the extirpated regions often occurs. Several bone morphogenetic proteins (BMPs), well-described inducers of ossification, are involved in bone healing. This study tested the hypothesis that a postoperative treatment with Noggin, an extracellular BMP inhibitor, can inhibit resynostosis in a rabbit model of human familial nonsyndromic craniosynostosis. MATERIALS AND METHODS: Thirty-one New Zealand white rabbits with bilateral coronal suture synostosis were divided into three groups: (1) suturectomy controls (n = 13); (2) suturectomy with BSA in a slow-resorbing collagen vehicle, (n = 8); and (3) suturectomy with Noggin in a slow-resorbing collagen vehicle (n = 10). At 10 days of age, a 3 x 15-mm coronal suturectomy was performed. The sites in groups 2 and 3 were immediately filled with BSA-loaded gel or Noggin-loaded gel, respectively. Serial 3D-CT scan reconstructions of the defects and standard radiographs were obtained at 10, 25, 42, and 84 days of age, and the sutures were harvested for histological analysis. RESULTS: Radiographic analysis revealed that Noggin-treated animals had significantly greater coronal suture marker separation by 25 days and significantly greater craniofacial length at 84 days of age compared with controls. 3D-CT analysis revealed that Noggin treatment led to significantly greater defect areas through 84 days and to increased intracranial volumes at 84 days of age compared with other groups. Histological analysis supported CT data, showing that the untreated and BSA-treated groups had significant healing of the suturectomy site, whereas the Noggin-treated group had incomplete wound healing. CONCLUSIONS: These data support our hypothesis that inhibition of BMP activity using Noggin may prevent postoperative resynostosis in this rabbit model. These findings also suggest that Noggin therapy may have potential clinical use to prevent postoperative resynostosis in infants with craniosynostosis.

Fetal exposure to sodium valproate associated with Baller-Gerold syndrome: case report and review of the literature.

CASE REPORT: We report three patients with a history of maternal valproate use during pregnancy who presented with a combination of metopic suture synostosis and upper limb malformations, which could be diagnosed as Baller-Gerold syndrome (BGS). The patients underwent surgical treatment for the craniofacial deformity, during which standard frontocranial reconstruction was performed. REVIEW OF THE LITERATURE: Only 32 patients have been reported in the world literature and these cases support the emerging view that BGS is not a distinct syndrome, but should instead be considered to be an heterogeneous phenotype with variable etiology. CONCLUSIONS: Our case series suggests for the first time that fetal sodium valproate exposure may also cause this phenotype.

Craniosynostosis and fetal exposure to sodium valproate.

OBJECT: Fetal valproate syndrome affects one in 10 children born to mothers who ingest sodium valproate regularly during pregnancy. It has been described as producing a combination of typical dysmorphic features and major organ system anomalies. Trigonocephaly is caused by premature fusion of the metopic suture and has not previously been described as a typical feature of the syndrome. The authors reviewed the cases of 2,220 children with craniosynostosis to examine the effect of maternal sodium valproate use on the fetus. METHODS: Case files of all 2,220 children were reviewed. The type and severity of each patient's craniosynostosis was assessed. Information about maternal health and medication use was obtained, and family interviews were conducted. Children underwent mental development assessment performed using standard tests both pre- and postoperatively. Detailed maternal health information was obtained in 1,676 cases. Of these, 17 mothers were found to have undergone regular treatment with sodium valproate monotherapy at the time of their pregnancies. No other antiepileptic medical regimen was found. All 17 children exhibited trigonocephaly. These patients' intelligence quotients (JQs) at the time of the most recent follow-up examination ranged from 45 to 100, with a mean of 75; IQs were significantly higher in patients who underwent surgery before reaching 6 months of age. CONCLUSIONS: Ideally any pregnancy in a woman being treated for epilepsy should be planned, and both an obstetrician and a neurologist should be consulted. In children born with fetal valproate syndrome, it is important to be aware of the possibility of metopic suture synostosis, which we believe should be considered part of the syndrome, because early surgical intervention may improve cognitive outcome.

[Metopic suture craniosynostosis: sodium valproate teratogenic effect. Case report]. / Cranioestenose da sutura metópica: efeito teratogênico do valproato de sódio. Relato de caso.

OBJECTIVE: the aim of this report is to warn that sodium valproate used during pregnancy can produce craniosynostosis in the newborn, particularly trigonocephaly. METHOD: we describe a case of trigonocephaly in a six month-old girl, daughter of a young non-smoker couple, whose mother had used phenobarbital 100 mg daily and sodium valproate 500 mg twice daily during the whole pregnancy. We also review current literature about this topic. RESULT: bone sclerosis over the metopic suture was confirmed during surgery. Bibliographical review yields previous reports on valproate teratogenicity, mainly determining metopic suture craniosynostosis. CONCLUSION: sodium valproate used during pregnancy can produce craniosynostosis by teratogenic effect, specially trigonocephaly (premature fusion of metopic suture).

Cranioestenose da sutura metópica: efeito teratogênico do valproato de sódio. Relato de caso / Metopic suture craniosynostosis: sodium valproate teratogenic effect. Case report

OBJETIVO: alertar que o uso de valproato de sódio durante a gravidez pode determinar cranioestenose no recém-nascido, em especial a trigonocefalia. MÉTODO: relato de um caso de trigonocefalia em menina de 6 meses, filha de pais jovens, näo fumantes e cuja mäe fez uso de fenobarbital 100 mg/dia e valproato de sódio 500 mg duas vezes/dia durante toda a gravidez. Foi realizada revisäo bibliográfica sobre o assunto. RESULTADO: no ato cirúrgico pôde-se confirmar a presença de esclerose óssea sobre a sutura metópica. A revisäo bibliográfica permitiu o encontro de relatos prévios sobre a teratogenicidade do valproato de sódio, que determina principalmente cranioestenose da sutura metópica. CONCLUSÄO: o uso de valproato de sódio durante a gravidez pode determinar como açäo teratogênica a cranioestenose, especialmente a trigonocefalia (fechamento precoce da sutura metópica)

Apparent cyclophosphamide (cytoxan) embryopathy: a distinct phenotype?

Cyclophosphamide (CP) is an alkylating agent widely used in treating cancer and autoimmune disease. CP is classified as a pregnancy risk factor D drug and is teratogenic in animals, but population studies have not conclusively demonstrated teratogenicity in humans. Six isolated reports of prenatally exposed infants with various congenital anomalies exist, but to date no specific phenotype has been delineated. The purpose of this report is to document a new case of in utero CP exposure with multiple congenital anomalies and to establish an apparent CP embryopathy phenotype. The mother had systemic lupus erythematosus and cyclophosphamide exposure in the first trimester. She also took nifedipine, atenolol, clonidine, prednisone, aspirin, and potassium chloride throughout pregnancy. The infant had growth retardation and multiple anomalies including microbrachycephaly, coronal craniosynostosis, hypotelorism, shallow orbits, proptosis, blepharophimosis, small, abnormal ears, unilateral preauricular pit, broad, flat nasal bridge, microstomia, high-arched palate, micrognathia, preaxial upper limb and postaxial lower limb defects consisting of hypoplastic thumbs, and bilateral absence of the 4th and 5th toes. Chromosomes were apparently normal. The reported cases of in utero exposure to cyclosposphamide shared the following manifestations with our patient: growth deficiency, developmental delay, craniosynostosis, blepharophimosis, flat nasal bridge, abnormal ears, and distal limb defects including hypoplastic thumbs and oligodactyly. We conclude that (a) cyclophosphamide is a human teratogen, (b) a distinct phenotype exists, and (c) the safety of CP in pregnancy is in serious question.

Teratogenic effects in a case of maternal treatment for acute myelocytic leukaemia--neonatal and infantile course.

Experience with the use of cytotoxic drugs in the first trimester of pregnancy is limited. We report on the clinical phenotype and infantile development of a girl born to a 36-year-old mother. Before recognition of pregnancy, the latter had been treated for acute myelocytic leukaemia receiving cytarabine, daunorubicin and doxorubicin at conception and cytarabine and thioguanine at about 35-37 days post conception. At delivery, there were severe brachycephaly, hypoplasia of the anterior cranial base and the midface as well as synostoses of both coronal and metopic sutures. Further findings included bilateral four-finger hands with hypoplastic thumbs and absent radii. This phenotype is reminiscent of the Baller-Gerold syndrome. The child, at present 15 months old, has had to undergo two operations for fronto-orbital advancement because of insufficient growth of the mid-face, nasal airway hypoplasia and increased intracranial pressure. Motor milestones are slightly retarded--neurodevelopment is otherwise normal. These findings are discussed in the context of the few previous reports and are particularly important for future genetic counselling.

Etiopathogenesis of craniosynostosis.

Craniosynostosis is both etiologically and pathogenetically heterogeneous. Known causes include monogenic and chromosomal disorders, fetal head constraint, teratogens (aminopterin, diphenylhydantoin, retinoic acid, valproic acid), metabolic diseases (hyperthyroidism, rickets, mucopolysaccharidoses, mucolipidoses), hematologic disorders (thalassemias, sickle cell anemia, congenital hemolytic icterus, polycythemia vera), and malformations (microcephaly, encephalocele, shunted hydrocephaly, holoprosencephaly).