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Dominique Renier

Publications and source records attributed to Dominique Renier.

At least 19 recordsLinked to original sources
PubMed2007

Pediatric craniopharyngiomas: classification and treatment according to the degree of hypothalamic involvement.

OBJECT: The current treatment of craniopharyngiomas is evolving into one of a multimodal approach in which the aim is disease control and improved preservation of quality of life (QOL). To date, an appropriate classification system with which to individualize treatment is absent. The objectives of this study were to identify preoperative prognostic factors in patients with craniopharyngiomas and to develop a risk-based treatment algorithm. METHODS: The authors reviewed data obtained in a retrospective cohort of 66 children (mean age 7.4 years, mean follow-up period 7 years) who underwent resection between 1984 and 2001. Postoperative recurrence rates, vision status, and endocrine function were consistent with those reported in the literature. The postoperative morbidity was related to hypothalamic dysfunction. The preoperative magnetic resonance imaging grade, clinically assessed hypothalamic function, and the sugeon's operative experience (p = 0.007, p = 0.047, p = 0.035, respectively) significantly predicted poor outcome. Preoperative hypothalamic grading was used in a prospective cohort of 22 children (mean age 8 years, mean follow-up period 1.2 years) treated between 2002 and 2004 to stratify patients according to whether they underwent gross-total resection (GTR) (20%), complete resection avoiding the hypothalamus (40%), or subtotal resection (STR) (40%). In cases in which residual disease was present, the patient underwent radiotherapy. There have been no new cases of postoperative hyperphagia, morbid obesity, or behavioral dysfunction in this prospective cohort. CONCLUSIONS: For many children with craniopharyngiomas, the cost of resection is hypothalamic dysfunction and a poor QOL. By using a preoperative classification system to grade hypothalamic involvement and stratify treatment, the authors were able to minimize devastating morbidity. This was achieved by identifying subgroups in which complete resection or STR, performed by an experienced craniopharyngioma surgeon and with postoperative radiotherapy when necessary, yielded better overall results than the traditional GTR.

Adolescent↗
PubMed2006

Mutation screening in patients with syndromic craniosynostoses indicates that a limited number of recurrent FGFR2 mutations accounts for severe forms of Pfeiffer syndrome.

Crouzon Syndrome (CS), Pfeiffer syndrome (PS) and the phenotypically related Jackson-Weiss (JW) variant are three craniosynostotic conditions caused by heterozygous mutations in Fibroblast Growth Factor Receptor (FGFR) genes. Screening a large cohort of 84 patients with clinical features of CS, PS or JW by direct sequencing of genomic DNA, enabled FGFR1, 2 or 3 mutation detection in 79 cases. Mutations preferentially occurred in exons 8 and 10 of FGFR2 encoding the third Ig loop of the receptor. Among the 74 FGFR2 mutations that we identified, four were novel including three missense substitutions causing CS and a 2 bp deletion creating a premature stop codon and producing JW phenotype. Five FGFR2 mutations were found in one of the two tyrosine kinase subdomains and one in the Ig I loop. Interestingly, two FGFR2 mutations creating cysteine residues (W290C and Y340C) caused severe forms of PS while conversion of the same residues into another amino-acid (W290G/R, Y340H) resulted in Crouzon phenotype exclusively. Our data provide conclusive evidence that the mutational spectrum of FGFR2 mutations in CS and PS is wider than originally thought. Genotype-phenotype analyses based on our cohort and previous studies further indicate that in spite of some overlap, PS and CS are preferentially accounted for by two distinct sets of FGFR2 mutations. A limited number of recurrent amino-acid changes (W290C, Y340C, C342R and S351C) is commonly associated with the most severe Pfeiffer phenotypes of poor prognosis.

Acrocephalosyndactylia↗
PubMed2006

Respiratory outcome of midface advancement with distraction: a comparison between Le Fort III and frontofacial monobloc.

Upper airway stenosis in patients with faciocraniosynostosis is very common and often severe. Midface advancement, either with a Le Fort III or concomitantly to a monobloc frontofacial advancement, may prevent a tracheotomy or result in its ablation. The amelioration of respiratory function appears to be much better if the midface advancement is combined with distraction osteogenesis, although large studies with long-term follow-up are rare. In this study, we reviewed the respiratory outcome between Le Fort III with distraction and monobloc advancement with distraction in 54 faciocraniosynostotic patients. Early respiratory results of both procedures were very good and stable at long-term follow-up. The choice between a Le Fort III and a monobloc procedure is made on the basis of presenting morphology, previous surgery, and age. Both can be expected to give a long-lasting improvement of upper airway obstruction.

Acrocephalosyndactylia↗
PubMed2006

Epidemiology and early predictive factors of mortality and outcome in children with traumatic severe brain injury: experience of a French pediatric trauma center.

OBJECTIVE: To describe the results of an integrated pre- and in-hospital approach to critical care in a large population of children with severe traumatic brain injury and to identify the early predictors of their outcome. DESIGN: A 9-yr retrospective review of the data of a trauma data bank. SETTING: Level III pediatric trauma center. PATIENTS: All children (1 month to 15 yrs) with severe traumatic brain injury (Glasgow Coma Scale </=8) hospitalized in our trauma center and followed until death or for >/=6 months after discharge. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Univariate and further multivariate analyses were performed to determine independent predictive factors of death and outcome at discharge and 6 months later. The Glasgow Outcome Scale was used to evaluate outcome; a poor outcome referred to Glasgow Outcome Scale >/=3. Receiver operating characteristic curves were drawn to determine the threshold values of predictors of death and outcome. Analysis concerned 585 children (67% male and 33% female). Mean age was 7 +/- 5 yrs. Predominant mechanisms of injury were road traffic accidents and falls. Mean values for Glasgow Coma Scale, Pediatric Trauma Score, and Injury Severity Score were 6 (3-8), 3 (-4,10), and 28 (4-75), respectively. Mortality rate was 22%; Glasgow Outcome Scale was <3 in 53% of the cases at discharge and 60% at 6 months. Multivariate analysis identified Glasgow Coma Scale, Injury Severity Score, and hypotension on arrival as independent predictors of death and poor outcome at discharge and at 6 months. Threshold values for death were 28 for Injury Severity Score and 5 for Glasgow Coma Scale. The same values were found for poor outcome, except for outcome at 6 months where threshold value for the Glasgow Coma Scale was 6. CONCLUSIONS: Initial hypotension, Glasgow Coma Scale, and Injury Severity Score are independent predictors of outcome in children with traumatic brain injury. Threshold values can be calculated for predicting poor outcome. These variables can be easily and detected early in this population and used for quality assessment.

Adolescent↗
PubMed2006

Respiratory outcome of mid-face advancement with distraction: a comparison between Le Fort III and frontofacial monobloc.

Upper airway stenosis in patients with faciocraniosynostosis is very common and often severe. Mid-face advancement, either with a Le Fort III or concomitantly to a monobloc frontofacial advancement, may prevent a tracheotomy or result in its ablation. The amelioration of respiratory function appears to be much better if the mid-face advancement is combined with distraction osteogenesis, although large studies with long-term follow-up are rare. In this study we reviewed the respiratory outcome between Le Fort III with distraction and monobloc advancement with distraction in 55 faciocraniosynostotic patients. Early respiratory results of both procedures were very good and stable at long-term follow-up. The choice between a Le Fort III and a monobloc procedure is made based on presenting morphology, previous surgery, and age. Both can be expected to give a long-lasting improvement of upper airway obstruction.

Adolescent↗
PubMed2006

Frontal lobe atrophy after prolonged frontal bone defect.

After a frontofacial monobloc in a 12-year-old Crouzon patient, the frontal bone was lost to infection. The patient did not attend postoperative appointments and was lost to follow-up. Nine years later, he reappeared requesting surgical reconstruction. This was performed satisfactorily with a titanium plate; however, it became apparent later that he had considerable atrophy of the frontal lobes and had developed the unstable behavior of patients who have undergone a frontal lobotomy. The atrophy would appear to be the consequence of the long-term absence of the frontal bones and the resultant repetitive frontal lobe microtrauma. Frontal infection and subsequent loss of the frontal bone is a recognized complication of monobloc advancement for faciocraniosynostosis and is mainly caused by the communication between the oronasal cavities and the cranial base. The frontal bone defect would normally be repaired after a delay of 6 months to a year with no significant sequelae. We present the unusual case of a patient whose frontal defect was not reconstructed for 9 years and who, as a result, developed frontal lobe atrophy and subsequent severe psychologic and behavioral difficulties.

Adult↗
PubMed2006

Postoperative cognitive outcome for synostotic frontal plagiocephaly.

OBJECT: The goals of this study were to evaluate the cognitive outcome after surgery for synostotic frontal plagiocephaly and to compare the effects of early (< 1 year of age) and late (> or = 1 year of age) surgical correction on intellectual development. METHODS: In a prospective study involving 220 patients, both preoperative and postoperative cognitive function were measured using developmental quotient (DQ) or intelligence quotient (IQ) determination. Preoperative intracranial pressure (ICP) was also measured, and the presence of the fibroblast growth factor receptor 3 (FGFR3) P250R mutation was assessed. CONCLUSIONS: Preoperative DQ/IQ was not affected by patient age at the time of surgery. There was no statistically significant difference in mean postoperative IQ between patients who underwent surgery before 1 year of age and those who underwent surgery at 1 year of age or older. In the latter group, there was a statistically significant increase in the incidence of elevated ICP (> or = 15 mm Hg in 16%), but no effect on cognitive outcome was observed. Likewise, there was no statistically significant correlation between the presence of the FGFR3 mutation and postoperative IQ. The indication for surgical correction appears to be largely cosmetic.

Age Factors↗
PubMed2005

Chiari malformation in craniosynostosis.

INTRODUCTION: Chiari malformation (CM) is a frequent finding in multisutural and syndromic craniosynostosis, occurring in 70% of patients with Crouzon's syndrome, 75% with oxycephaly, 50% with Pfeiffer's syndrome and 100% with the Kleeblattschädel deformity. The pathogenesis of this condition and rationale for treatment are still controversial. DISCUSSION: Since its first description in 1972, several factors have been cited to play a role in inducing CM. In the light of recent publications, the roles of premature fusion of cranial vault and cranial base sutures, of congenital anomalies of the cerebellum and brain stem, of raised intracranial pressure, of venous hypertension and of hydrocephalus are reviewed. Evaluation and management of CM are also discussed. CONCLUSION: Chiari malformation appears to be an acquired and progressive condition that develops in the first months of life, because of a disproportion between hindbrain growth and an abnormally small posterior fossa, a consequence of the premature fusion of lambdoid and cranial base sutures. Venous hypertension caused by stenosis of the jugular foramen can also be present in these patients, resulting in intracranial hypertension and/or hydrocephalus. Careful MRI evaluation is recommended for the forms of craniosynostosis at a high risk of developing hindbrain herniation. The selection of posterior cranial vault expansion as the first surgical procedure is advocated. In selected cases, treatment of the posterior cranial deformity by occipital vault remodelling and treatment of the Chiari-like deformity by suboccipital decompression can be carried out using the same surgical procedure.

Arnold-Chiari Malformation↗
PubMed2005

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.

Craniosynostoses↗
PubMed2005

Combined high cervical spine and brain stem injuries: a complex and devastating injury in children.

BACKGROUND: In young children, high cervical spine injuries (HCSI) can result in inaugural reversible, cardiac arrest or apnea. We noted in children sustaining such injuries an unusual incidence of associated brain stem injuries and defined a special pattern of combined lesions. METHODS: Children with HSCI surviving inaugural cardiac arrest/apnea were selected for a retrospective analysis of a trauma data bank. Epidemiologic, clinical, and radiological characteristics, and outcome were reviewed and compared with those of the rest of the trauma population with severe neurologic injuries (defined by a Glasgow Coma Scale < 8). RESULTS: Thirteen children with HCSI above the C3 spinal level and inaugural cardiac arrest/apnea were identified and compared with 819 severely head injured children without HSCI. Mean age was 4.7 +/- 2.9 years, and median Glasgow Coma Scale was 3 (3-6) after resuscitation. Initial standard x-ray views missed spine injuries in 6 patients. Spiral computed tomographic (CT) scan showed cervical fracture-dislocations associated with diffuse brain lesions and brain stem injury in all patients. Children with combined lesions had more frequent severe facial and skull base fractures compared with the rest of the population. They also were younger and sustained more frequent severe distracting injury to the neck than the rest of the population. Mortality rate (69%) was 2.6-fold higher than that observed in children without HCSI. In survivors, none demonstrated spinal cord injury resulting in persistent peripheral neurologic deficits, but only one achieved a good recovery. CONCLUSIONS: Combined HCSI and brain stem injuries must be suspected in young children sustaining a severe distracting injury to the craniocervical junction. Early recognition of these catastrophic injuries by systematic spiral cervical spine and brain stem computed tomographic scan evaluation is mandatory.

Algorithms↗
PubMed2005

Preoperative chemotherapy in children with high-risk medulloblastomas: a feasibility study.

OBJECT: The authors set out to evaluate the feasibility and effectiveness of preoperative chemotherapy in treating high-risk medulloblastomas. METHODS: Between 1997 and 2000, 21 children with high-risk medulloblastomas (M > or = 2 and/or T3b/T4 according to the Chang classification) were treated consecutively in a pilot study. The protocol began with treatment of the hydrocephalus and confirmation of the diagnosis. Tumor surgery was performed either after conventional chemotherapy (eight patients) or after subsequent high-dose chemotherapy (HDCT; 11 patients). Two children with early leptomeningeal progression died before surgery. Craniospinal irradiation was applied to children older than 5 years of age, whereas younger children received local irradiation only. Hydrocephalus was present in 17 children and was treated with ventriculocisternostomy in 13 and shunt insertion in four. A biopsy procedure was performed with a stereotactic frame in 10 children, an open surgery was performed in four, an endoscope was used during the ventriculocisternostomy in three, and the diagnosis was made based on cerebrospinal fluid cytological analysis in two. The response rate to the first two courses of chemotherapy was 71% for the tumor and 59% for the metastases. The pathological analysis of the residue after chemotherapy showed true medulloblastomas in seven cases, complete neuroglial maturation in three cases, and a mixture of both in nine cases. Three-year progression-free survival was 37% and was significantly better in children older than 5 years of age. There was one death related to the HDCT. CONCLUSIONS: Preoperative chemotherapy is feasible and safe in children with high-risk medulloblastomas provided that the hydrocephalus can be treated at diagnosis. A larger study is warranted to ensure that the high response rate to adjuvant chemotherapy can lead to better surgical results and survival advantage.

Cerebellar Neoplasms↗
PubMed2005

Genetic considerations in nonsyndromic midline craniosynostoses: a study of twins and their families.

OBJECT: The origins of both sagittal synostosis (scaphocephaly) and metopic synostosis (trigonocephaly) remain unclear. Genetic and environmental factors probably play a role. Twin and family data of patients with these conditions are presented. METHODS: Records of 860 patients with scaphocephaly and 394 with trigonocephaly were examined for prevalence of twin birth and family history. Concordance rates of disease in monozygotic (MZ) and dizygotic (DZ) twins were compared. A family history of disease was present in 5.7% of children with scaphocephaly and in 6.8% with trigonocephaly. The frequency of twins was 4.2% in sagittal synostosis and 6.8% in metopic synostosis, which is higher than in the normal population. Twenty-eight of 38 twin pairs with a scaphocephalic proband were identified to be DZ and 10 were confirmed to be MZ (MZ/DZ ratio 0.36). Twenty of 27 twin pairs with trigonocephaly were DZ and seven were MZ (MZ/DZ ratio 0.35). Concordance rates were higher in the MZ group, 30% for scaphocephaly and 43% for trigonocephaly (chi2 = 14.4091, p = 0.0001). There was a strong prevalence of boys, with a frequency of 79.1% with scaphocephaly and 75.8% with trigonocephaly. Twinning was more frequent among affected boys in both groups. CONCLUSIONS: A midline craniosynostosis is more likely to develop in twins compared with singletons. A genetic component is supported by the higher risk in MZ twins. The presence of an environmental component is reinforced by the high rate of twinning, the normal MZ/DZ ratio, and a less than 100% concordance rate in MZ twins.

Child↗
PubMed2004

Surgical evacuation of acute subdural hematoma improves cerebral hemodynamics in children: a transcranial Doppler evaluation.

OBJECTIVE: The objective was to evaluate cerebral hemodynamics in young children with acute subdural hematoma (SDH) and the impact of surgical treatment using transcranial Doppler (TCD). DESIGN: The design was a prospective study of infants with SDH requiring surgical evacuation. SETTING: The setting was the neuro intensive care unit of a university hospital. INTERVENTIONS: Indications for surgical evacuation were based upon clinical and radiological arguments. Surgery included emergency needle aspiration followed by external or/and internal shunting as required. A TCD evaluation was performed before needle aspiration, and after each surgical drainage procedure. It included a pressure provocation test to assess cerebral compliance. Preoperative and postoperative middle cerebral artery (MCA) velocities, Gosling pulsatility (PI) and Pourcelot resistivity (RI) indexes and compliance were compared with Student's t-test, or Fisher's exact test as indicated. MEASUREMENTS AND MAIN RESULTS: Out of 26 infants, 23 (88%) had injuries that had possibly been inflicted, and 3 had accidental injuries. Initial TCD evaluation demonstrated intracranial hypertension with decreased diastolic velocity, increased PI and RI, and decreased compliance. Surgical evacuation resulted in statistically significant improvement in cerebral hemodynamics (diastolic velocity: 17.2+/-10 cm/s vs. 31.1+/-10 cm/s, p<0.0015, PI: 2.5+/-1.3 vs. 1.4+/-0.8, p<0.002, RI: 0.8+/-0.2 vs. 0.6+/-0.1, p<0.005) in all but 3 infants, who eventually died. Surgical drainage (primary shunting or external drainage) was needed in 23 infants and resulted in further improvement in cerebral hemodynamics. Finally, 73% of the infants made a good recovery. CONCLUSIONS: Children with acute bilateral HSD have a high incidence of increased intracranial pressure as assessed by TCD. Surgical evacuation improves cerebral hemodynamics. TCD could be used for assessing the need for, and the efficiency of surgical drainage.

Blood Flow Velocity↗
PubMed2004

Successful use of biosorb osteofixation devices in 165 cranial and maxillofacial cases: a multicenter report.

Bioabsorbable osteofixation devices were developed to avoid problems associated with metals. Bioabsorbable devices are mostly made of the polymers polylactide, polyglycolide, and their copolymers [polyglycolide-co-polylactide and P(L/DL)LA]. Using the technique of self-reinforcement of bioabsorbable materials, it is possible to manufacture osteofixation devices with ultra high strength. Self-reinforced polyglycolide-co-polylactide 80/20 was selected to make devices (Biosorb PDX) for this study because of its favorable degradation characteristics. The aim of this study was to evaluate the efficacy of using self-reinforced polyglycolide-co-polylactide 80/20 (Biosorb) plates and screws in the fixation of osteotomies in craniomaxillofacial surgery. In a prospective study, 165 patients (161 children and 4 adults) were operated on in four European Union centers (Paris, Innsbruck, London, and Oulu) from May 1, 1998 to January 31, 2002. Indications included correction of dyssynostotic deformities (n = 159), reconstruction of bone defects after trauma (n = 2), tumor removal (n= 2), and treatment of encephalocele (n = 2). Plates used were 0.8, 1, or 1.2 mm thick, and screws had an outer (thread) diameter of 1.5 or 2 mm and a length of 4, 6, or 8 mm. Tacks had an outer diameter of 1.5 or 2 mm and a length of 4 or 6 mm. During surgery, the devices were easy to handle and apply and provided stable fixation apart from 2 cases. Postoperative complications occurred in 12 cases (7.3%), comprising infection (n = 6), bone resorption (n = 4), diabetes insipidus (n = 1), delayed skin wound healing/skin slough (n = 2), and liquorrhea (n = 1). Accordingly, self-reinforced polyglycolide-co-polylactide 80/20 (Biosorb) plates and screws can be used safely and with a favorable outcome in corrective cranioplasties, especially in infants and young children.

Absorbable Implants↗
PubMed2003

Ophthalmologic findings in suspected child abuse victims with subdural hematomas.

PURPOSE: Shaken baby syndrome consists of intracranial and intraocular hemorrhages in young children in the absence of signs of direct head trauma. Because it has major medicolegal implications, it must be distinguished from accidental trauma. This study aimed to determine the ophthalmologic manifestations and their natural course in child abuse victims and whether ophthalmologic examination can help to distinguish shaken babies from children with accidental impact head trauma. DESIGN: Prospective comparative observational case series. METHODS: A prospective study was conducted from January 1996 to September 2001 on 241 consecutive infants hospitalized for a subdural hematoma to determine the frequency and the type of ocular abnormalities encountered. At admission, 186 children were highly presumed to have been shaken (group 1), 38 children had signs of direct head trauma without any relevant history of trauma (group 2), some of them having been possibly shaken, whereas 7 children had proven severe accidental head trauma (group 3). RESULTS: Intraocular hemorrhages were the main finding. Their shape, laterality, and size were not significantly different in groups 1 and 2. However they were significantly more frequent in nonaccidental head trauma than in infants with head impact (77.5% versus 20%). None of the group 3 children had intraocular hemorrhage. Eighty-two percent of intraocular hemorrhages resolved within 4 weeks. CONCLUSIONS: Intraocular hemorrhages are frequent in shaken babies but not specific of this syndrome. When associated with a subdural hematoma, they are strongly suggestive of shaken neglect. They are rare in pediatric accidental head trauma.

Child Abuse↗
PubMed2003

Comparison of perioperative blood salvage and postoperative reinfusion of drained blood during surgical correction of craniosynostosis in infants.

BACKGROUND: The surgical correction of craniosynostosis may be associated with extensive blood loss and transfusion. The aim of this study was to compare the efficacy of the perioperative use of the continuous autotransfusion system (CATS group) and of the postoperative use of the CBCII ConstaVac(R) system (CV group) to reduce homologous transfusion in infants during repair of craniosynostosis. METHODS: Two groups of consecutive infants, weighing <10 kg, and scheduled for the surgical correction of craniosynostosis, were compared retrospectively according to the blood salvaging system used: CATS group and CV group. The primary endpoint was the comparison of the total volume of homologous blood transfused. RESULTS: There was no significant difference between the CV (n = 69) and the CATS (n = 135) groups with regard to physical, preoperative and postoperative data, except for the type of craniosysnostosis with more scaphocephaly in the CV group (P = 0.03). No significant difference in blood loss and homologous transfusion was observed between the two groups during the perioperative period. Two subgroups of patients were also compared: a subgroup including patients operated on with a linear craniectomy for scaphocephaly, and a subgroup including all other patients. There was also no significant difference in blood loss and homologous transfusion between the CV and the CATS groups for these two subgroups of patients. CONCLUSION: Our results suggest that the postoperative use of the CBCII ConstaVac(R) system is as efficient as the perioperative use of the CATS(R) system for reducing homologous blood transfusion during repair of craniosynostosis in infants weighing <10 kg.

Blood Loss, Surgical↗
PubMed2002

Saethre-Chotzen syndrome: notable intrafamilial phenotypic variability in a large family with Q28X TWIST mutation.

Saethre-Chotzen syndrome is an autosomal dominant disease characterized by craniosynostosis, ptosis, and limb and external ear abnormalities. Variable expressivity is a well-known phenomenon in this disorder. A large Indian family has been recently identified as carrying a nonsense TWIST mutation (Q28 X) in 17 members, of whom 16 were examined in detail. Only 4 (25%) of the patients showed patent craniostenosis, namely, oxycephaly. The penetrance of craniosynostosis in this family is lower than previously reported in the literature. Fifteen patients (93%) had moderate to severe ptosis. Minor limb and external ear abnormalities were present in most patients. Eyelid features were the hallmark of the disease for 12 members of the family, suggesting that mutations in TWIST may lead to a phenotype with mainly palpebral features and no craniostenosis. The clinical analysis of this large family clearly illustrates the significant variable expressivity, probably related to haploinsufficiency because of the TWIST mutation. This phenotypic variability remains unclear but could be the result of modifier genes and/or genetic background effect, as noticed previously in the transgenic twist-null heterozygous mice.

Acrocephalosyndactylia↗