Neuropathologic findings in a case of OFDS type VI (Váradi syndrome)

Oral-facial-digital syndrome type VI (OFDS VI) or Váradi syndrome is a rare autosomal-recessive disorder distinguished from other oral-facial-digital syndromes by metacarpal abnormalities with central polydactyly and by cerebellar abnormalities. Histopathologic characterization of the cerebellar abnormalities has not been described previously. We describe the neuropathologic findings in a stillborn, 21-week estimated gestational age (EGA) male fetus diagnosed antenatally with signs of OFDS VI. Autopsy findings included: facial abnormalities, postaxial central polydactyly of the right hand, bilateral bifid toes, and absence of cerebellar vermis with hypoplasia of the hemispheric cortex. Microscopic analysis of the cerebellum demonstrated absence of the subpial granular cell layer and disruption or dysgenesis of the glial architecture. These histopathologic findings suggest that a primary neuronal or glial cell defect, rather than an associated Dandy-Walker malformation, may account for the cerebellar abnormalities in this form of oral-facial-digital syndrome. Am. J. Med. Genet. 77:38–42, 1998. © 1998 Wiley-Liss, Inc.     

Oral–facial–digital syndrome type VI (Váradi syndrome): Further clinical delineation

Cerebellar anomalies are consistent findings in patients with the oral–facial–digital syndrome type VI (Váradi syndrome) in addition to variable facial and oral changes, and polysyndactyly of hands and feet. We report 3 unrelated patients with this entity who have a hypoplastic cerebellar vermis shown by magnetic resonance imaging (MRI), as well as clinical signs of cerebellar defect. Polydactyly of the hands is characterized by a central Y-shaped metacarpal. Clinically recurrent episodes of tachypnea and hyperpnea are remarkable. Postnatal growth is delayed with short stature in all 3 patients possibly due to growth hormone deficiency in one of them. In contrast to reported patients who are all severely mentally retarded, one of our patients is of normal intelligence. Type VI oral-facial-digital syndrome is an autosomal-recessive trait and may be detected prenatally.     

Ritscher‐Schinzel cranio‐cerebello‐cardiac (3C) syndrome: Report of four new cases and review

Ritscher‐Schinzel syndrome, also known as the 3C syndrome, is a rare, autosomal recessive syndrome characterized by craniofacial, cerebellar, and cardiac anomalies. Cardiac manifestations include ventricular septal defect, atrial septal defect, tetralogy of Fallot, double outlet right ventricle, hypoplastic left heart, aortic stenosis, pulmonic stenosis and other valvular anomalies. Central nervous system anomalies include Dandy‐Walker malformation, cerebellar vermis hypoplasia and enlargement of the cisterna magna. Craniofacial abnormalities seen are cleft palate, ocular coloboma, prominent occiput, low‐set ears, hypertelorism, down‐slanting palpebral fissures, depressed nasal bridge and micrognathia. Dandy‐Walker malformation, posterior fossa cyst, hydrocephalus and congenital heart defect are common malformations that may occur in isolation or as a part of many syndromes. Accurate genetic diagnosis and counseling require detailed analysis of the external as well as the internal anatomy and knowledge of the relative frequencies of various malformations in syndromes that may have overlapping clinical signs. We have had the opportunity recently to study four cases of the Ritscher‐Schinzel syndrome. A review of all reported cases is presented and an attempt made to define the minimum diagnostic criteria for the Ritscher‐Schinzel syndrome. Of the nine craniofacial anomalies commonly reported as a part of the Ritscher‐Schinzel syndrome, we consider two i.e., cleft palate and ocular coloboma, to be readily and objectively ascertainable. The other seven craniofacial traits, however, are somewhat subjective, require expert interpretation and are sometimes difficult to ascertain in a newborn or stillborn fetus. These are prominent forehead, prominent occiput, hypertelorism, down‐slanting palpebral fissures, low‐set ears, depressed nasal bridge and micrognathia. At least four of these were present in all cases that had a secure diagnosis of the Ritscher‐Schinzel syndrome. Thus, the criteria we propose to establish the diagnosis of the Ritscher‐Schinzel syndrome in a chromosomally normal sporadic case are the presence of cardiac malformation other than isolated patent ductus arteriosus, cerebellar malformation, and cleft palate or ocular coloboma or four of the following seven findings: prominent forehead, prominent occiput, hypertelorism, down‐slanting palpebral fissures, low‐set ears, depressed nasal bridge, and micrognathia. © 2001 Wiley‐Liss, Inc.     

Cerebral defects confirm midline developmental field disturbances in supernumerary der(22), t(11;22) syndrome

We describe a girl with midline defects and distal limb anomalies, who had a supernumerary der(22) syndrome. The presence of some anomalies identifying the midline defects, led us to review all patients reported up to now, with interesting results. We point out the particular finding of midline defects in CNS only, in patients studied by autopsy or neuroradiologic imaging.     

Variability versus heterogeneity in syndromal hypothalamic hamartoblastoma and related disorders: Review and delineation of the Cerebro-Acro-Visceral Early lethality (CAVE) multiplex syndrome

We report on a case of neonatal hypothalamic hamartoblastoma with holoprosencephaly, Hirschsprung disease, and tetramelic postaxial polydactyly. Twenty-seven previous cases of congenital hypothalamic embryonic tumours with associated congenital defects are reviewed. A classification in isolated, associated, and syndromal forms is proposed. The difficulties encountered in differential diagnosis between the syndromal form (mainly represented by the Pallister-Hall syndrome) and related diseases as Smith-Lemli-Opitz type II, holoprosencephaly-polydactyly, orofaciodigital type VI and hydrolethalus syndromes are outlined. Two pathogenic mechanisms are discussed: a classical pleiotropic model and single sequence model. The latter is sufficient to delineate syndromal hypothalamic hamartoblastoma. With the former, syndromal hypothalamic hamartoblastoma cannot be clearly recognized in the absence of a CNS tumour, a child with syndromal hypothalamic hamartoblastoma cannot be reliably diagnosed as Pallister-Hall rather than another MCA syndrome, and, ultimately, the existence of Pallister-Hall syndrome could be questioned, as it could only be the extreme expression of one or several other syndromes. As this hypothesis cannot be proven or disproven at this point, the authors suggest creating the concept of multiplex phenotype. “Cerebro-Acro-Visceral Early lethality multiplex syndrome” is suggested to encompass all the ambiguous cases. Within this complex, an operative classification key is proposed. © 1992 Wiley-Liss, Inc.     

Frameshift mutation in the cartilage‐derived morphogenetic protein 1 (CDMP1) gene and severe acromesomelic chondrodysplasia resembling Grebe‐type chondrodysplasia

Grebe‐type chondrodysplasia exhibits a severe form of limb shortening and appendicular bone dysmorphogenesis. Here we report a family with seven males and six females who inherited the disorder in an autosomal recessive fashion. While the carrier parents did not exhibit any apparent skeletal abnormalities, all affected patients had a similar phenotype with unaffected axial and craniofacial bones. Since mutations in the cartilage‐derived morphogenetic protein 1 (CDMP1) gene have been reported in similar acromesomelic chondrodysplasias, we examined genomic DNA from affected and normal subjects for possible mutations in CDMP1. In affected subjects, an insertion of a C at nucleotide 297 of the coding sequence was discovered. This insertion produced a shift in the reading frame at amino acid residue 99, causing premature termination of the polypeptide six amino acids downstream. DNA samples from 41 control subjects did not show this mutation. The truncated CDMP1 protein in these subjects is predicted to cause a total loss of its signaling function. The present report confirms that CDMP1 plays an important role in the regulation of axial bone growth during development and suggests that its absence does not impair other developmental processes.© 2002 Wiley‐Liss, Inc.     

Allelic imbalance at the LKB1 (STK11) locus in tumours from patients with Peutz-Jeghers' syndrome provides evidence for a hamartoma–(adenoma)–carcinoma sequence

Patients with Peutz-Jeghers' syndrome (PJS) develop hamartomatous gastrointestinal polyps and characteristic pigmentation, as a result of germline mutations in the LKB1 gene. The hamartomas in PJS were long considered to be without malignant potential. There is, however, accumulating epidemiological evidence to suggest that PJS predisposes to cancers at several different sites (colon, pancreas, breast, ovary, testis, and cervix), although large enough patient samples are rarely available to prove this. Allelic imbalance [allele loss, loss of heterozygosity (LOH)] has previously been reported in a small number of PJS polyps, suggesting that LKB1 acts as a tumour suppressor in these tumours. This study confirms allelic loss at LKB1 in PJS polyps and shows that LOH also occurs in cancers of the colon, breast, and cervix in PJS patients. Allele loss was additionally found in a colonic adenoma from a PJS patient, strongly suggesting the existence of a hamartoma–(adenoma)–carcinoma sequence in tumourigenesis. These results provide molecular evidence that PJS patients are predisposed to cancers at several sites, as a direct result of selection for loss of the ‘wild-type’ LKB1 allele in tumours. Given the rare involvement of LKB1 in sporadic cancers, these data also suggest that the indirect effect on cancer risk (or ‘bystander effect’) proposed for hamartomas in juvenile polyposis does not apply to carcinomas in PJS. Copyright © 1999 John Wiley & Sons, Ltd.     

Novel mutations in the ciliopathy-associated gene CPLANE1 (C5orf42) cause OFD syndrome type VI rather than Joubert syndrome

Mutations in CPLANE1 (previously known as C5orf42) cause Oral-Facial-Digital Syndrome type VI (OFD6) as well as milder Joubert syndrome (JS) phenotypes. Seven new cases from five unrelated families diagnosed with pure OFD6 were systematically examined. Based on the clinical manifestations of these patients and those described in the literature, we revised the diagnostic features of OFD6 and include the seven most common characteristics: 1) molar tooth sign, 2) tongue hamartoma and/or lobulated tongue, 3) additional frenula, 4) mesoaxial polydactyly of hands, 5) preaxial polydactyly of feet, 6) syndactyly and/or bifid toe, and 7) hypothalamic hamartoma. By whole or targeted exome sequencing, we identified seven novel germline recessive mutations in CPLANE1, including missense, nonsense, frameshift and canonical splice site variants, all causing OFD6 in these patients. Since CPLANE1 is also mutated in JS patients, we examined whether a genotype-phenotype correlation could be established. We gathered and compared 46 biallelic CPLANE1 mutations reported in 32 JS and 26 OFD6 patients. Since no clear correlation between paired genotypes and clinical outcomes could be determined, we concluded that patient's genetic background and gene modifiers may modify the penetrance and expressivity of CPLANE1 causal alleles. To conclude, our study provides a comprehensive view of the phenotypic range, the genetic basis and genotype-phenotype association in OFD6 and JS. The updated phenotype scoring system together with the identification of new CPLANE1 mutations will help clinicians and geneticists reach a more accurate diagnosis for JS-related disorders.     

<Emphasis Type="Italic">CKN1</Emphasis> (MIM 216400): mutations in Cockayne syndrome type A and a new common polymorphism

We found that a subject with Cockayne syndrome type A was a compound heterozygote for two new mutations in CKN1 (MIM 216400): a missense mutation (A205P) and a nonsense (E13X) mutation. We also identified and characterized a new common single nucleotide polymorphism in CKN1 in five groups.     

Musculocontractural Ehlers‐Danlos Syndrome (former EDS type VIB) and adducted thumb clubfoot syndrome (ATCS) represent a single clinical entity caused by mutations in the dermatan‐4‐sulfotransferase 1 encoding CHST14 gene

We present clinical and molecular findings of three patients with an EDS VIB phenotype from two consanguineous families. The clinical findings of EDS kyphoscoliotic type (EDS type VIA and B) comprise kyphoscoliosis, muscular hypotonia, hyperextensible, thin and bruisable skin, atrophic scarring, joint hypermobility and variable ocular involvement. Distinct craniofacial abnormalities, joint contractures, wrinkled palms, and normal urinary pyridinoline ratios distinguish EDS VIB from EDS VIA. A genome‐wide SNP scan and sequence analyses identified a homozygous frameshift mutation (NM_130468.2:c.145delG, NP_569735.1:p.Val49*) in CHST14, encoding dermatan‐4‐sulfotransferase 1 (D4ST‐1), in two Turkish siblings. Subsequent sequence analysis of CHST14 identified a homozygous 20‐bp duplication (NM_130468.2:c.981_1000dup, NP_569735.1:p.Glu334Glyfs*107) in an Indian patient. Loss‐of‐function mutations in CHST14 were recently reported in adducted thumb–clubfoot syndrome (ATCS). Patients with ATCS present similar craniofacial and musculoskeletal features as the EDS VIB patients reported here, but lack the severe skin manifestations. By identifying an identical mutation in patients with EDS VIB and ATCS, we show that both conditions form a phenotypic continuum. Our findings confirm that the EDS‐variant associated with CHST14 mutations forms a clinical spectrum, which we propose to coin as “musculocontractural EDS” and which results from a defect in dermatan sulfate biosynthesis, perturbing collagen assembly. Hum Mutat 31:1–7, 2010. © 2010 Wiley‐Liss, Inc.     

Single-strand conformation polymorphism (SSCP) analysis of the COL3A1 gene detects a mutation that results in the substitution of glycine 1009 to valine and causes severe Ehlers–Danlos syndrome type IV

A single base mismatch was detected by single-strand conformation polymorphism (SSCP) of the collagen type III gene in a patient with Ehlers-Danlos syndrome type IV. The patient's fibroblasts secreted both normal and slowly migrating type III procollagen molecules. Two-dimensional CNBr peptide mapping suggested that the defect was localised in the CB9 peptide or the C-propeptide region of the α1(III)-chain. Analysis of a set of restriction-endonuclease-digested fragments of an amplified cDNA sequence encoding CB9, identified a single-strand conformation polymorphism and localized it within a region of 79 bp corresponding to the carboxyl-terminal end of the CB9 peptide of the α1(III)-chain. DNA sequence analysis demonstrated that the patient was heterozygous for a point mutation converting G to T at base pair 3440 of the collagen α₁,(III) cDNA resulting in the substitution of glycine with valine at amino acid position 1009 of the α₁(III)-chain. The mutation in this patient lies within a region of mutations at the carboxyl-terminal end of the type III collagen α-helix which all produce a severe “acrogeric” form of EDS IV. © 1994 Wiley-Liss, Inc.