Fanconi anemia in a child previously diagnosed as Baller-Gerold syndrome

Clinically diverse and perinatally lethal syndromes with urorectal septum malformation sequence

Urorectal septum malformation sequence (URSMS) is characterized by a spectrum of anomalies of the urogenital system, hindgut and perineum. It is presumed to be a constellation of an embryonic defect. Herein, we analyzed the clinically diverse syndromes associated with URSMS in our perinatal evaluation unit. We reviewed fetuses with URSMS in referrals for perinatal autopsy over a period of 3 years. Chromosomal microarray and genome sequencing were performed whenever feasible. Literature was reviewed for syndromes or malformations with URSMS. We ascertained URSMS in 12 of the 215 (5%) fetuses. Nine fetuses (75%) had complete URSMS and remainder had partial/intermediate URSMS. Eleven fetuses had malformations of other systems that included: cerebral ventriculomegaly; right aortic arch with double outlet right ventricle; microcephaly with fetal akinesia deformation sequence; ventricular septal defect and radial ray anomaly; thoraco-abdominoschisis and limb defects; myelomeningocele; spina bifida and fused iliac bones; omphalocele; occipital encephalocele; lower limb amelia and cleft foot. We report on six fetuses with recurrent and five fetuses with unique malformations/patterns where URSMS is a component. Exome sequencing (one family) and genome sequencing (eight families) were performed and were nondiagnostic. Additionally, we review the literature for genetic basis of this condition. URMS is a clinically heterogeneous condition and is a component of several multiple malformation syndromes. We describe several unique and recurrent malformations associated with URSMS.

Phenotypic Overlap of Roberts and Baller-Gerold Syndromes in Two Patients With Craniosynostosis, Limb Reductions, and ESCO2 Mutations

Baller-Gerold (BGS, MIM#218600) and Roberts (RBS, MIM#268300) syndromes are rare autosomal recessive disorders caused, respectively, by biallelic alterations in RECQL4 (MIM^*603780) and ESCO2 (MIM^*609353) genes. Common features are severe growth retardation, limbs shortening and craniofacial abnormalities which may include craniosynostosis. We aimed at unveiling the genetic lesions underpinning the phenotype of two unrelated children with a presumptive BGS diagnosis: patient 1 is a Turkish girl with short stature, microcephaly, craniosynostosis, seizures, intellectual disability, midface hemangioma, bilateral radial and thumb aplasia, tibial hypoplasia, and pes equinovarus. Patient 2 is an Iranian girl born to consanguineous parents with craniosynostosis, micrognathism, bilateral radial aplasia, thumbs, and foot deformity in the context of developmental delay. Upon negative RECQL4 test, whole exome sequencing (WES) analysis performed on the two trios led to the identification of two different ESCO2 homozygous inactivating variants: a previously described c.1131+1G>A transition in patient 1 and an unreported deletion, c.417del, in patient 2, thus turning the diagnosis into Roberts syndrome. The occurrence of a Baller-Gerold phenotype in two unrelated patients that were ultimately diagnosed with RBS demonstrates the strength of WES in redefining the nosological landscape of rare congenital malformation syndromes, a premise to yield optimized patients management and family counseling.

Craniosynostosis and radial ray defect: a rare presentation of 22q11.2 deletion syndrome

A newborn with bilateral coronal craniosynostosis, hypoplastic thumbs, imperforate anus, and prenatal growth restriction was evaluated and given the clinical diagnosis of Baller-Gerold syndrome (BGS). While confirmatory testing of RECQL4 was pending, the infant developed unexplained hypocalcemia, prompting testing for a 22q11.2 deletion. Subsequently, the infant was found to have a 22q11.2 deletion, and was negative for an RECQL4 mutation. We therefore conclude that 22q11.2 deletion syndrome can present with findings resembling the BGS phenotype.

Rothmund-Thomson syndrome helicase, RECQ4: on the crossroad between DNA replication and repair

RECQ proteins are conserved DNA helicases in both prokaryotes and eukaryotes. The importance of the RECQ family helicases in human health is demonstrated by their roles as cancer suppressors that are vital for preserving genome integrity. Mutations in one of the RECQ family proteins, RECQ4, not only result in developmental abnormalities and cancer predispositions, but are also linked to premature aging. Therefore, defining the function and regulation of the RECQ4 protein is fundamental to our understanding of both the aging process and cancer pathogenesis. This review will summarize the clinical effect of RECQ4 in human health, and discuss the recent progress and debate in defining the complex molecular function of RECQ4 in DNA metabolism.

Hereditary and familial syndromes of bone and blood. Genetic pathways, diagnostic pitfalls

Numerous metabolic disorders, teratogenic agents, and in utero infections lead to congenital bone disease and malformation. This review focuses on hereditary and familial disorders of bone with particular emphasis on impaired hematopoiesis, myelofibrosis, pathologic fractures, and dysmorphology of the forearm and craniofacial structures. The severity of bone disease and marrow dysfunction of any given disorder may vary considerably from one affected individual to the next, and intrapersonal variability over time may be substantial as well. Both can impart difficulty to the appropriate evaluation and delay the correct diagnosis. Many of these disorders are phenotypically quite similar but require very different therapeutic intervention.

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.

Revisiting the craniosynostosis-radial ray hypoplasia association: Baller-Gerold syndrome caused by mutations in the RECQL4 gene

Baller-Gerold syndrome (BGS) is a rare autosomal recessive condition with radial aplasia/hypoplasia and craniosynostosis (OMIM 218600). Of >20 cases reported so far, a few appear atypical and have been reassigned to other nosologic entities, including Fanconi anaemia, Roberts SC phocomelia, and Pfeiffer syndromes after demonstration of corresponding cytogenetic or molecular abnormalities. Clinical overlap between BGS, Rothmund-Thomson syndrome (RTS), and RAPADILINO syndrome is noticeable. Because patients with RAPADILINO syndrome and a subset of patients with RTS have RECQL4 mutations, we reassessed two previously reported BGS families and found causal mutations in RECQL4 in both. In the first family, four affected offspring had craniosynostosis and radial defect and one of them developed poikiloderma. In this family, compound heterozygosity for a R1021W missense mutation and a g.2886delT frameshift mutation of exon 9 was found. In the second family, the affected male had craniosynostosis, radial ray defect, poikiloderma, and short stature. He had a homozygous splice site mutation (IVS17-2A>C). In both families, the affected offspring had craniosynostosis, radial defects, and growth retardation, and two developed poikiloderma. Our results confirm that BGS in a subgroup of patients is due to RECQL4 mutations and could be integrated into a clinical spectrum that encompasses RTS and RAPADILINO syndrome.

Another TWIST on Baller-Gerold syndrome

Baller-Gerold syndrome is characterized by craniosynostosis and preaxial upper limb malformations. Wide heterogeneity exists with regard to the presence of additional anomalies. Most of the 31 reported cases involve other malformations, including cardiac, Central Nervous System (CNS), and urogenital anomalies. Baller-Gerold syndrome is thought to have autosomal recessive inheritance. However, Gripp et al. [1999: Am. J. Med. Genet. 82:170-176] recently provided the first evidence for autosomal dominant inheritance with variable expressivity and severity. A nonsense mutation was found in TWIST, a gene associated with Saethre-Chotzen syndrome (SCS). Here we report on a male Caucasian patient of nonconsanguineous parents, with synostosis of the coronal, metopic, and sagittal sutures, and bilateral radial ray hypoplasia. The patient's small, round ears with prominent crus helices, and cervical anomalies are common features of SCS. The father had very mild features of SCS. We identify direct paternal transmission of a novel missense TWIST mutation in the highly conserved Helix II domain of this bHLH-family gene. This report lends further support to the recent findings by Gripp et al. [1999]. Future TWIST mutational analysis on patients with craniosynostosis and radial ray involvement will shed light on whether Baller-Gerold syndrome should be a distinct entity or some cases should be reclassified as a heterogeneous form of SCS.

TWIST gene mutation in a patient with radial aplasia and craniosynostosis: further evidence for heterogeneity of Baller-Gerold syndrome

The term Baller-Gerold syndrome was coined by Cohen [1979: Birth Defects 15(5B): 13-63] to designate the phenotype of craniosynostosis and radial aplasia. It is thought to be a rare autosomal recessive condition, which, in some patients, presents with additional abnormalities, such as polymicrogyria, mental retardation or anal atresia. A phenotypic overlap of Baller-Gerold and Roberts-SC phocomelia syndrome was noted when a patient with bicoronal synostosis and bilateral radial hypoplasia was found to have premature centromere separation, a finding characteristic of Roberts syndrome [Huson et al.,1990: J Med Genet 27:371-375]. Other cases of presumed Baller-Gerold syndrome were rediagnosed as Fanconi pancytopenia, Rothmund-Thomson syndrome or VACTERL association. These reports led to a narrowed redefinition of Baller-Gerold syndrome based on the exclusion of cytogenetic and hematopoetic abnormalities and the absence of additional malformations in patients with craniosynostosis and preaxial upper limb abnormalities. Here we report on a patient with unilateral radial aplasia and bicoronal synostosis without additional malformations and without chromosome breakage, who fits this narrow definition of Baller-Gerold syndrome. We identified a novel TWIST gene mutation in this patient, a Glu181Stop mutation predicting a premature termination of the protein carboxy-terminal to the helix 2 domain. This report provides further evidence that Baller-Gerold is of heterogeneous cause, and a thorough evaluation is indicated to identify a possibly more specific diagnosis, including Saethre-Chotzen syndrome. This differential diagnosis is of particular importance, as it is an autosomal dominant trait. Therefore, the recurrence risk for parents of an affected child can be 50% if one parent carries the mutation, as opposed to the 25% recurrence risk for autosomal recessive inheritance. Offspring of the affected patient also have a 50% risk to inherit the mutation, while the risk to bear an affected offspring for an autosomal recessive trait is very low.

Baller-Gerold syndrome associated with congenital portal venous malformation

We report a 4 year old boy in whom the clinical features of craniosynostosis and bilateral absent radii led to a diagnosis of Baller-Gerold syndrome. Additional congenital abnormalities included midface hypoplasia, atrial and ventricular septal defects, right hydronephrosis, partial sacral agenesis, and anterior ectopic anus. Evidence of portal venous hypertension was present from 8 months and a congenital portal venous malformation was discovered at 2 years. This is the first reported case of Baller-Gerold syndrome associated with a congenital portal venous malformation. We discuss the diagnostic confusion between this syndrome and other overlapping malformation syndromes and propose optimal evaluation strategies aimed at clarifying the nosology of these syndromes.

Fanconi anemia in brothers initially diagnosed with VACTERL association with hydrocephalus, and subsequently with Baller-Gerold syndrome

Two brothers with presumed Baller-Gerold syndrome, one of whom was previously diagnosed with the association of vertebral, cardiac, renal, limb anomalies, anal atresia, tracheo-esophageal fistula (VACTERL) association with hydrocephalus, were evaluated for chromosome breakage because of severe thrombo cytopenia in one of them. Spontaneous and clastogen-induced breakage was markedly increased in both patients as compared to control individuals. Clinical manifestations and chromosome breakage, consistent with Fanconi anemia, in patients with a prior diagnosis of either Baller-Gerold syndrome, reported earlier in one other patient [Farrell et al., 1994: Am J Med Genet 50:98-99], or with VACTERL association with hydrocephalus, recently reported in 3 patients [Toriello et al., 1991: Proc Greenwood Genet Center 11:142; Porteus et al., 1992: Am J Med Genet 43:1032-1034], underline the clinical heterogeneity of Fanconi anemia and raise the question of whether these syndromes are distinct disorders or phenotypic variations of the same disease.