Clinical and molecular analysis of Grebe acromesomelic dysplasia in an Omani family

Grebe syndrome is a rare autosomal recessive acromesomelic dysplasia. The syndrome was studied clinically, radiographically, and genetically in an Omani family with four affected children. The affected persons had normal axial skeletons, severely shortened, and deformed limbs with severity increasing in a proximo-distal gradient, and subluxated joints. The humeri and femora were hypoplastic with distal malformations. The radii/ulnae were shortened and deformed whereas carpal bones were invariably rudimentary or absent. The tibiae appeared rudimentary; fibulae were absent in two children, and some tarsal and metatarsal bones were absent. The proximal and middle phalanges were absent while the distal phalanges were present. The father and mother had short first metacarpal and middle phalynx of the fifth finger and hallux valgus respectively. Transition A1137G and deletion delG1144 mutations in the gene encoding the cartilage-derived morphogenetic protein-1 (CDMP-1) were identified in this family. The A1137G is a silent mutation coding for lysine, whereas the delG1144 predicts a frameshift mutation resulting in a presumable loss of the CDMP-1 biologically active carboxy-terminal domain. The affected siblings were homozygous for the delG1144 mutation while parents were heterozygous.     

Reply to Seller and Bobrow

This paper describes seven persons in a family affected with an autosomal dominant syndrome of short stature with mesomelic shortness of upper and lower limbs, abnormal carpal and tarsal bones, hypoplastic or absent middle phalanges of hands and feet, and delayed coalescence of bipartite calcanei. All affected relatives are of normal intelligence, are free of eye problems, and have a normal skull, spine, shoulders, and hips. The digits of the hands and feet are short, broad, and angulated. The hypoplastic or absent middle phalanges effectively result in one interphalangeal joint for each digit, with decreased mobility. The bones of the carpus and tarsus coalesce with increasing age. None of the previously described syndromes or brachydactylies encompasses the findings noted in this kindred.     

An autosomal dominant syndrome of short stature with mesomelic shortness of limbs, abnormal carpal and tarsal bones, hypoplastic middle phalanges, and bipartite calcanei

This paper describes seven persons in a family affected with an autosomal dominant syndrome of short stature with mesomelic shortness of upper and lower limbs, abnormal carpal and tarsal bones, hypoplastic or absent middle phalanges of hands and feet, and delayed coalescence of bipartite calcanei. All affected relatives are of normal intelligence, are free of eye problems, and have a normal skull, spine, shoulders, and hips. The digits of the hands and feet are short, broad, and angulated. The hypoplastic or absent middle phalanges effectively result in one interphalangeal joint for each digit, with decreased mobility. The bones of the carpus and tarsus coalesce with increasing age. None of the previously described syndromes or brachydactylies encompasses the findings noted in this kindred.     

Autosomal dominant onychodystrophy and anonychia with type B brachydactyly and ectrodactyly

A family is reported with nail dysplasia and/or absent nails, long and broad finger-like thumbs, camptodactyly and absent fingers. Radiological studies revealed hypoplasia of metacarpals, metatarsals and distal phalanges. Two affected individuals have absent metacarpals and phalanges. The clinical and radiological features may constitute a distinct syndrome of autosomal dominant onychodystrophy and anonychia with Julia Bell brachydactyly type B.     

Hereditary index finger polydactyly: phenotypic, radiological, dermatoglyphic, and genetic findings in a large family.

Index finger polydactyly in a Turkish family is reported. The transmission of the malformation fits the pattern of regular autosomal dominant inheritance. Some of the affected individuals had one or two phalanges on their first digits, but all had triphalangeal second fingers. Subjects with polydactyly had very interesting dermatoglyphs, such as an extra a triradius under the super-numerary index finger, the proximal radiant of this triradius (an extra A-line) ending on the radial border of the hand, and arch tibials in the hallucal areas. The carpal bones, beginning with os multangulum majus, or alternatively with the extra one were articulated with two metacarpals. A similar finding was found in the feet.     

Mutation in the cartilage-derived morphogenetic protein-1 (CDMP1) gene in a kindred affected with fibular hypoplasia and complex brachydactyly (DuPan syndrome)

The present authors have previously described a consanguineous Pakistani family with fibular hypoplasia and complex brachydactyly (DuPan syndrome) inherited as an autosomal recessive trait. All affected individuals showed either reductions or absence of bones in the limbs, and appendicular bone dysmorphogenesis with unaffected axial bones. Obligate heterozygote parents were phenotypically normal. Mutations in the cartilage-derived morphogenetic protein 1 (CDMP1) gene have been reported in two acromesomelic chondrodysplasias (i.e. Hunter-Thompson type and Grebe type) which are phenotypically related to DuPan syndrome. CDMP1, a member of the transforming growth factor beta super-family of secreted signalling molecules, has been reported to regulate limb patterning and distal bone growth. Therefore, the present authors examined genomic DNA from the family with DuPan syndrome for mutations in the CDMP1 gene. Affected individuals were homozygous for a missense mutation, T1322C, in the coding region of the CDMP1 gene. This mutation was not found in 44 control subjects of Pakistani origin. The T1322C change predicts a leu441pro substitution in the mature domain of the CDMP1 protein. This is likely to cause a conformational change in the CDMP1 protein that influences the expression of genes which are required for normal bone development. This finding extends the spectrum of phenotypes produced by defects in the CDMP1 gene.     

Familial progressive sinoatrial and atrioventricular conduction disease of adult onset with sudden death,dilated cardiomyopathy,and brachydactyly. A new type of heart-hand syndrome?

We identified a family with 10 affected members in four generations suffering from adult-onset progressive sinoatrial and atrioventricular conduction disease, sudden death due to ventricular tachyarrhythmia, dilated cardiomyopathy, and a unique type of brachydactyly with mild hand involvement (short distal, middle, proximal phalanges and clinodactyly) and more severe foot involvement (short distal, proximal phalanges and metatarsal bones, short or absent middle phalanges, terminal symphalangism, duplication of the bases of the second metatarsals, extra ossicles, and syndactyly). The phenotype differences from other reported genetic abnormalities and linkage exclusion of Holt-Oram syndrome, ulnar-mammary syndrome, brachydactyly type B or Robinow syndrome, and cardiac conduction disease or Brugada syndrome loci suggest that we report on a new hereditary heart-hand syndrome.     

Limb/pelvis hypoplasia/aplasia with skull defect (Schinzel phocomelia): distinctive features and prenatal detection.

Schinzel phocomelia syndrome is characterized by limb/pelvis hypoplasia/aplasia: specifically, intercalary limb deficiencies and absent or hypoplastic pelvic bones. The phenotype is similar to that described in a related multiple malformation syndrome known as Al-Awadi/Raas-Rothschild syndrome. The additional important feature of large parietooccipital skull defects without meningocele, encephalocele, or other brain malformation has thus far been reported only in children with Schinzel phocomelia syndrome. We recently evaluated a boy affected with Schinzel phocomelia born to nonconsanguineous healthy parents of Mexican origin. A third-trimester fetal ultrasound scan showed severe limb deficiencies and an absent pelvis. The infant died shortly after birth. Dysmorphology examination, radiographs, and autopsy revealed quadrilateral intercalary limb deficiencies with preaxial toe polydactyly; an absent pelvis and a 7 x 3-cm skull defect; and extraskeletal anomalies including microtia, telecanthus, micropenis with cryptorchidism, renal cysts, stenosis of the colon, and a cleft alveolar ridge. A normal 46,XY karyotype was demonstrated, and autosomal recessive inheritance was presumed on the basis of previously reported families. This case report emphasizes the importance of recognizing severe pelvic and skull deficiencies (either post- or prenatally) in differentiating infants with Schinzel phocomelia from other multiple malformation syndromes that feature intercalary limb defects, including thalidomide embryopathy and Roberts-SC phocomelia.     

Camera G,Baldi M,Strisciuglio P,Concolino D,Mastroiacovo P,Baffico M. 2001. Occurrence of thanatophoric dysplasia type I (R248C) and hypochondroplasia (N540K) mutations in two patients with achondroplasia phenotype. Am J Med Genet 104:277–281.

Grebe‐Quelce‐Salgado chondrodystrophy is an autosomal recessive non‐lethal skeletal dysplasia. Affected individuals have normal head, neck, and trunk skeleton, relatively normal humeri and femora, short and deformed radii, ulnae, tibiae, and fibulae, and severe abnormalities of hands and feet. Polydactyly is frequent. Digits present as globular appendages and are characteristic of the condition. The disease is caused by a missense mutation in the gene encoding cartilage‐derived morphogenetic protein‐1 (CDMP‐1). Most cases described in the literature are from Brazil and, among these, all had ancestors from a particular region in the state of Bahia. We describe two cases of Grebe‐Quelce‐Salgado chondrodystrophy visualized by prenatal ultrasound. The patients presented in this report do not descend from the population of Bahia and, to our knowledge, case two is the only case with prenatal clinical diagnosis in a family with no previously affected children. © 2002 Wiley‐Liss, Inc.     

Metacarpophalangeal analysis in Crouzon syndrome: Additional evidence for phenotypic convergence with the acrocephalosyndactyly syndromes

Crouzon syndrome (CS) is characterized by premature craniosynostosis, orbital proptosis, and midfacial hypoplasia and is related to the acrocephalosyndactylies (ACS) with limb abnormalities. In CS the hands are considered to be normal, but a previous report indicated that there is consistent alteration in the proportions of the bones of the hands, as shown by metacarpophalangeal analysis (MCPP), in at least some cases of CS. The purpose of this study was to extend these findings by examining affected individuals and their supposedly unaffected first degree relatives. If CS does have an effect on hands, then this should only be evident in the affected individuals and, presuming complete penetrance, not present in their unaffected relatives. PA hand films were taken on 12 CS subjects and 16 of their normal relatives. The lengths of the metacarpals and phalanges were measured and the measurements standardized for age and sex by conversion to z-scores using published normal standards. Mean pattern profiles for the 2 groups were plotted. In CS the phalanges, especially the first and second proximal phalanges and the first distal phalanx, were shorter than average, and shorter than those of unaffected relatives. The metacarpals were not significantly smaller than the reference means in CS. The 19 hand measurements were entered into a step-wise forward discriminant function analysis (DFA) to develop a model that would discriminate between CS subjects and their normal first degree relatives. The function generated used the measurements of 8 hand bones to classify correctly CS subjects and their normal relatives 100% of the time. This study confirmed that there is a radiographically detectable abnormality of the hands in CS and that, at least in this sample, relatives did not display such abnormalities. Therefore, it seems that CS shares postcranial effects with true ACS and that these effects are, like the other aspects of CS, fully penetrant. Am. J. Med. Genet. 73:61–66, 1997. © 1997 Wiley-LIss, Inc.     

Grebe‐Quelce‐Salgado chondrodystrophy: Prenatal diagnosis of two new cases in unrelated families in Southern Brazil

Grebe‐Quelce‐Salgado chondrodystrophy is an autosomal recessive non‐lethal skeletal dysplasia. Affected individuals have normal head, neck, and trunk skeleton, relatively normal humeri and femora, short and deformed radii, ulnae, tibiae, and fibulae, and severe abnormalities of hands and feet. Polydactyly is frequent. Digits present as globular appendages and are characteristic of the condition. The disease is caused by a missense mutation in the gene encoding cartilage‐derived morphogenetic protein‐1 (CDMP‐1). Most cases described in the literature are from Brazil and, among these, all had ancestors from a particular region in the state of Bahia. We describe two cases of Grebe‐Quelce‐Salgado chondrodystrophy visualized by prenatal ultrasound. The patients presented in this report do not descend from the population of Bahia and, to our knowledge, case two is the only case with prenatal clinical diagnosis in a family with no previously affected children. © 2002 Wiley‐Liss, Inc.     

New autosomal recessive syndrome of severe microcephaly and skeletal anomalies including posterior rib-gap defects

We describe two female fetuses conceived by a nonconsanguineous couple. The pregnancies were interrupted at 31 and 26 weeks of gestation, respectively, because of severe microcephaly. Postmortem X-ray and autopsy studies showed in both fetuses: 1) severe intrauterine growth retardation; 2) facial anomalies characterized by severe microcephaly, sloping forehead, low set and posteriorly angulated ears, prominent eyes, down-slanting palpebral fissures, large nose, small mouth with full lips, and mild microretrognathia; 3) severe brain hypoplasia that was more pronounced in the second fetus; 4) severe rib hypoplasia with posterior rib-gap defects and in case 2 hypoplasia of several bones (right clavicle, right radius and ulna, several phalanges of hands and feet); 5) contracture at large joints. No other visceral malformations were observed, and chromosomes were normal in patient 2 and parents. This phenotype has some similarities with different syndromic entities but an identical malformation syndrome seems not to have been described previously. Autosomal recessive inheritance is the most likely cause of this putative “new syndrome.” Am. J. Med. Genet. 80:429–434, 1998. © 1998 Wiley-Liss, Inc.     

A HOXA13 allele with a missense mutation in the homeobox and a dinucleotide deletion in the promoter underlies Guttmacher syndrome

Guttmacher syndrome, a dominantly inherited combination of distal limb and genital tract abnormalities, has several features in common with hand-foot-genital syndrome (HFGS), including hypoplastic first digits and hypospadias. The presence of features not seen in HFGS, however, including postaxial polydactyly of the hands and uniphalangeal 2(nd) toes with absent nails, suggests that it represents a distinct entity. HFGS is caused by mutations in the HOXA13 gene. We have therefore re-investigated the original Guttmacher syndrome family, and have found that affected individuals are heterozygous for a novel missense mutation in the HOXA13 homeobox (c.1112A>T; homeodomain residue Q50L), which arose on an allele already carrying a novel 2-bp deletion (-78-79delGC) in the gene's highly conserved promoter region. This deletion produces no detectable abnormalities on its own, but may contribute to the phenotype in the affected individuals. The missense mutation, which alters a key residue in the recognition helix of the homeodomain, is likely to perturb HOXA13's DNA-binding properties, resulting in both a loss and a specific gain of function.     

Short rib syndrome—Beemer type in sibs

The short rib (polydactyly) syndrome Beemer type is a rare lethal osteochondrodysplasia characterized clinically by short limbs, median cleft upper lip and palate, narrow thorax, and protuberant abdomen, and radiologically by short ribs, short and bowed long bones, and mild platyspondyly. Two affected female sibs are described, one having a preaxial polydactyly of the feet. The differentiation with the short rib syndrome Majewski type relies mainly on the radiological appearance of the tibia. Molecular biology may eventually prove whether the 2 conditions are truly separate entities or not.     

Short rib syndrome--Beemer type in sibs

The short rib (polydactyly) syndrome Beemer type is a rare lethal osteochondrodysplasia characterized clinically by short limbs, median cleft upper lip and palate, narrow thorax, and protuberant abdomen, and radiologically by short ribs, short and bowed long bones, and mild platyspondyly. Two affected female sibs are described, one having a preaxial polydactyly of the feet. The differentiation with the short rib syndrome Majewski type relies mainly on the radiological appearance of the tibia. Molecular biology may eventually prove whether the 2 conditions are truly separate entities or not.     

Clinical and molecular heterogeneity of syndromic hypothalamic hamartoma

Two children are presented who have a distinct syndrome of multiple buccolingual frenula, a stiff and short fifth finger with small nails, a hypothalamic hamartoma, mild to moderate neurological impairment, and mild endocrinological symptoms. No variant assessed to be pathogenic or likely pathogenic was detected in the GLI3 gene in either child. This syndrome appears to be distinct from the inherited Pallister–Hall syndrome associated with GLI3 variants, which is characterized by hypothalamic hamartoma, mesoaxial polydactyly, and other anomalies. In the individuals described here, manifestations outside of the central nervous system were milder and the mesoaxial polydactyly, which is common in individuals with Pallister–Hall syndrome, was absent. Instead, these children had multiple buccolingual frenula together with the unusual appearance of the fifth digit. It remains unclear whether these two individuals represent a separate nosologic entity or if they represent a milder manifestation of one of the more severe syndromes associated with a hypothalamic hamartoma.     

De novo complete trisomy 5p: clinical and neuroradiological findings

A Thai mother and son with distal symphalangism and other associated abnormalities are reported. Distal and middle phalanges of fingers and toes 2-5 were either aplastic/hypoplastic or fused between the corresponding digits. The second fingers and fourth fingernails were most severely affected in both patients. The mother's hands were less severely affected; the middle and distal phalanges of her hands were malformed and fused. Besides the absence of fusion lines, the shape of the fused middle and distal phalanges was quite different from that of other types of fusion, i.e., fused bones in both patients did not maintain the normal configuration of bone, referring to as "middle-distal phalangeal complex". Distal symphalangism was observed in toes 2-5 of the mother and in toe 3 of the son. Both patients had additional clinical manifestations such as narrowing of the zygomatic arch, dental pulp stone, microdontia of a mandibular permanent central incisor, cone-shaped epiphyses of middle phalanges of fingers, and absence of scaphoid, trapezium, trapezoid, and pisiform bones. Mutation analysis of NOG and ROR2, the genes responsible for proximal symphalangism and brachydactyly type B, respectively, was negative.     

Brachydactylic multiple delta phalanges plus syndrome

Delta phalanges are unusual, shortened bones of the hands and feet with abnormal epiphyses and diaphyses. Here, we report on a patient with a unique multiple congenital anomaly syndrome that includes brachydactyly consisting of multiple delta phalanges in several digits of the hands and feet. The patient, who was born to consanguineous parents, had several other congenital anomalies, including butterfly vertebrae, craniofacial dysmorphism, and coarctation of the aorta. We have called this distinctive condition "brachydactylic multiple delta phalanges plus syndrome." Although no other member of the family had obvious hand or foot anomalies, several siblings had other malformations. Possible modes of inheritance in this family include variable expression of a recessive or de novo dominant condition.     

Grebe chondrodysplasia and brachydactyly in a family

A family is reported in which various skeletal abnormalities have been segregating over three generations. The Great-grandfather (11) of the consultand had features consistent with Grebe chondrodysplasia. The other members of the family have brachydactyly, radiologically characterised by short first metacarpals and short middle phalanges of the index and little fingers. The possibility of association of familial brachydactyly and Grebe chondrodysplasia is discussed. An attempt has been made to deal with the genetic counselling problem in this particular family.