Short rib syndrome--Beemer type in sibs

Expanding the genetic architecture and phenotypic spectrum in the skeletal ciliopathies

Defects in the biosynthesis and/or function of primary cilia cause a spectrum of disorders collectively referred to as ciliopathies. A subset of these disorders is distinguished by profound abnormalities of the skeleton that include a long narrow chest with markedly short ribs, extremely short limbs, and polydactyly. These include the perinatal lethal short-rib polydactyly syndromes (SRPS) and the less severe asphyxiating thoracic dystrophy (ATD), Ellis-van Creveld (EVC) syndrome, and cranioectodermal dysplasia (CED) phenotypes. To identify new genes and define the spectrum of mutations in the skeletal ciliopathies, we analyzed 152 unrelated families with SRPS, ATD, and EVC. Causal variants were discovered in 14 genes in 120 families, including one newly associated gene and two genes previously associated with other ciliopathies. These three genes encode components of three different ciliary complexes; FUZ, which encodes a planar cell polarity complex molecule; TRAF3IP1, which encodes an anterograde ciliary transport protein; and LBR, which encodes a nuclear membrane protein with sterol reductase activity. The results established the molecular basis of SRPS type IV, in which mutations were identified in four different ciliary genes. The data provide systematic insight regarding the genotypes associated with a large cohort of these genetically heterogeneous phenotypes and identified new ciliary components required for normal skeletal development.

New case of Beemer-Langer syndrome

We present the case of a male infant born at 37 weeks gestation with multiple congenital anomalies, including hydrops fetalis, facial and visceral abnormalities, short ribs, and short limbs without polydactyly. We believe that this represents a further case of the Beemer-Langer syndrome, a relatively recently described form of lethal osteochondrodysplasia with an autosomal recessive mode of inheritance. This case also showed some less frequently described anomalies, including arachnoid cysts of the brain and short intestines.

Jeune asphyxiating thoracic dystrophy and short-rib polydactyly type III (Verma-Naumoff) are variants of the same disorder

Jeune syndrome (JS) and short-rib polydactyly syndrome type III (SRP type III) are autosomal recessive disorders characterized by short ribs and polydactyly. They are distinguished from each other by the more severe radiological and histological bone findings as well as the occurrence of facial anomalies, ambiguous genitalia, and occasionally, cloacal abnormalities in SRP type III. We present a family in which two children have mild JS and one has SRP type III as evidence that JS and SRP type III are variants of the same disorder. The intrafamilial variability may reflect the effects of modifying loci on gene expression.

Short rib-polydactyly syndrome: more evidence of a continuous spectrum

We report a fetus with radiological features of the four established types of short rib-polydactyly syndrome (SRPS). The phenotype of this fetus supports the previously suggested hypothesis that the different subtypes of the short rib and polydactyly syndrome are not single entities, but rather, part of a continuous spectrum with variable expressivity.

Cardiac malformations in patients with oral-facial-skeletal syndromes: clinical similarities with heterotaxia

Oral-facial-skeletal (OFS) syndromes include short rib-polydactyly (SRP) and oral-facial-digital (OFD) syndromes. Congenital heart defect (CHD), mainly atrioventricular canal defect (AVCD), is a cardinal finding in the Ellis-van Creveld (EVC) syndrome, but it occurs only occasionally in other SRP and OFD syndromes. The cardiac characteristics of all patients with OFS syndromes evaluated at our hospital from January 1986 to April 1997 were analyzed and compared with published reports. Ten patients with EVC syndrome, one with McKusick-Kaufman syndrome, and one with OFD syndrome type II had AVCD. Eight patients (67%) had a common atrium, eight (67%) a persistent left superior vena cava (LSVC) draining into the left atrium because of an unroofed coronary sinus in five (42%), and left-sided obstructive lesions in three (25%). One patient with EVC syndrome had AVCD, common atrium, double outlet right ventricle, persistent LSVC associated with "asplenia syndrome," visceral heterotaxia, and right isomerism. The combination of CHDs found in the personal series of OFS syndromes suggests pathogenetic similarity with heterotaxia syndromes. Published results also corroborate the association between OFS syndromes and CHDs usually occurring in heterotaxia. Molecular studies could shed light on the genetic mechanisms implicated in the cause of the OFS and heterotaxia syndromes.

A prehistoric example of polydactyly from the Iron Age site of Simbusenga, Zambia

Human burials, dated AD 1100-1500, were examined from the Iron Age site of Simbusenga, located some 35 miles northwest of Victoria Falls in Zambia. Pedal polydactyly was discovered in the fragmentary remains of a young adult of indeterminate sex aged 14-25. The preaxial form of polydactyly is indicated with bilateral involvement of the first metatarsals. There is incomplete hypoplastic duplication of both first metatarsals with broad heads for the metatarsal-phalangeal joints. No digital malformations were found in the other seven individuals with feet and/or hands from the site. Several studies point to autosomal dominance for cases of isolated polydactyly, but inheritance and patterning of preaxial polydactyly are still incompletely understood. The condition is also found in conjunction with genetic malformation syndromes such as Acrocephalypolysyndactyly, Lambotte, Oro-facio-digital, and VATER. High frequencies of polydactyly are reported for African and African-American populations, but further analysis reveals that the bulk of previously reported cases of polydactyly are representative of the postaxial form as opposed to the preaxial expression seen here.

Short rib-polydactyly syndrome in twins: Beemer-Langer type with polydactyly

We present premature female twin fetuses with concordant extremely shortened ribs, short limbs, macrocephaly, median cleft upper lip and facial dysmorphism. Based on radiological criteria and the pattern of associated abnormalities, a lethal short rib-polydactyly syndrome (Beemer-Langer type) was diagnosed. The differential diagnosis of this entity is discussed.

Jeune syndrome with tongue lobulation and preaxial polydactyly, and Jeune syndrome with situs inversus and asplenia: compound heterozygosity Jeune-Mohr and Jeune-Ivemark?

We report on a male infant with internal hydrocephalus, absence of corpus callosum, papillomas and lobulation of the tongue, notches of the alveolar ridges, short ribs, dysplastic pelvis, hypospadias, short limbs with bowed long tubular bones and postaxial polydactyly of hands, and preaxial polydactyly in one foot. Radiologically this case shares manifestations with Jeune syndrome; the tongue lobulation and the preaxial polydactyly are similar to findings in Mohr syndrome, or short-rib polydactyly syndrome (SRPS), type Majewski. In addition, a female newborn presented with manifestations of Jeune and Ivemark syndromes. One explanation for this overlap may be compound heterozygosity for these syndromes.

De novo 17q paracentric inversion mosaicism in a patient with Beemer-Langer type short rib-polydactyly syndrome with special consideration to the classification of short rib polydactyly syndromes

A de novo 17q paracentric inversion mosaicism is detected in a fetus with type IV short rib (polydactyly) syndrome (Beemer-Langer). The cytogenetic finding in our case suggests a possible location of the gene or cluster of linked genes responsible for SR (P) S type IV to 17q21 or 17q23. Since this chromosome abnormality has not been described in short rib polydactyly syndromes and the existence of type IV SR (P) S has been controversial, the literature of this entity is reviewed with special consideration to the classification of short rib polydactyly syndromes.

Further delineation of the Beemer-Langer syndrome using concordance rates in affected sibs

Six familial cases of the Beemer-Langer syndrome (BLS) were analyzed to further elucidate the spectrum and frequency of anomalies observed in this disorder. Preaxial polydactyly was found in 3/6 affected sibs, and, therefore, its frequency previously may have been underestimated. Some patients, described as infants affected with the Majewski syndrome (MS) or "atypical" short rib-polydactyly conditions, may indeed have BLS. A high frequency of brain defects (16/26) and cleft tongue, oral frenula, and/or natal teeth (13/29) widens the list of typical findings in this syndrome. The specific type of tibial defect seems to be the most important discrimination of the MS and the BLS.

Short rib-polydactyly syndrome and pericentric inversion of chromosome 4

We report on a newborn infant with clinical and radiological manifestations of some type of short rib-polydactyly syndrome who died soon after birth. Chromosomal studies on peripheral blood lymphocytes and chondrocytes demonstrated an apparently balanced pericentric inversion of chromosome 4 (present in the mother also). This association may have occurred by chance but, if not, the chromosomal breakpoints could interrupt the gene responsible for short rib-polydactyly syndromes, or else be related to the mechanism of short rib-polydactyly syndromes.

Lethal short rib-polydactyly syndromes: further evidence for their overlapping in a continuous spectrum

We report two new unrelated infants with short rib-polydactyly syndrome (SRPS) whose clinical and radiological features overlap the four established forms of lethal SRPS, so that it is difficult to classify them into any one particular type. One of the babies had one of the most radiologically severe SRPS ever published. The patients presented here support the previously reported hypothesis that this group of disorders might be a continuous spectrum rather than separate entities.

Short rib-polydactyly syndrome (SRPS) with anencephaly and other central nervous system anomalies: a new type of SRPS or a more severe expression of a known SRPS entity?

We describe two patients with short rib-polydactyly syndrome (SRPS) from two unrelated Spanish families. These patients present clinical and radiological characteristics that overlap those of the different established types of SRPS. In addition, one patient had anencephaly and the other patient had severe brain abnormalities with a family history of an older sister with anencephaly, and a brother diagnosed with SRPS. This second family is interesting in that the two affected brothers present with different clinical and radiological findings; for example, one had ovoid tibiae and the other did not. This particular family shows that intrafamiliar variation is also observed within SRPS. It remains unsettled whether these cases might be considered a new type of SRPS or a variant of an established entity or whether the differences between the SRPS represent variability or heterogeneity. Molecular studies may answer this question in the near future.

Proliferation and collagen biosynthesis of osteoblasts and chondrocytes in short rib syndrome type beemer

We report on a case of lethal short-limbed skeletal dysplasia with extremely short ribs, median cleft upper lip and palate, malrotation of intestine, lung hypoplasia with bilateral segmentation defect, atrial septum defect, union of distal urethra and vagina, and complex brain malformations. Based on radiological criteria and the pattern of associated abnormalities a short rib syndrome without polydactyly (Type Beemer) was diagnosed. Morphologically, the growth plate showed a reduced proliferation zone and an enlarged zone of hypertrophic cartilage. In addition, islands of persistent hypertrophic cartilage were present even in the metaphysis. In monolayer cell cultures supplemented with 10% fetal calf serum proliferation was normal in articular chondrocytes, reduced in costal chondrocytes, and elevated in osteoblasts from the patient. Clonal growth of costal and articular chondrocytes in methylcellulose could be stimulated normally by insulin-like growth factor-I (IGF-I), IGF-II, and human growth hormone (hGH). However, the response to transforming growth factor beta 1 (TGF-beta 1) was markedly elevated in articular chondrocytes of the patient compared to those of 3 fetal controls. Quantitative collagen synthesis in both osteoblasts and chondrocytes from the patient did not differ significantly from that of controls. Osteoblasts synthesized predominantly collagen I and minor amounts of collagen III, chondrocytes synthesized primarily collagen II. All collagen chains including CNBr-peptides of collagen II showed normal migration in PAA gel electrophoresis.

New findings in short rib syndrome

This white infant, born at 37 weeks of gestation, had a large cranium, bilateral anophthalmia, a midline cleft lip and palate, hypoplastic chest with short ribs, slightly protuberant abdomen, short limbs, bilateral single transverse palmar creases, a single umbilical artery, normal female external genitalia, normal (46 XY) chromosomes, and radiographic findings suggesting a short-rib (polydactyly) syndrome type IV (Beemer-Langer). Autopsy showed pulmonary hypoplasia, bilateral renal cystic dysplasia, intrahepatic bile duct cysts with periportal fibrosis, pancreatic cysts, absent internal genitalia, an atrophic optic chiasm, absent optic nerves, a single left anterior cerebral artery, polymicrogyria, and fusion of the frontal lobes, preoptic region, mammillary bodies, and thalami.

Lethal short rib syndrome of the Beemer type without polydactyly

A new case of Beemer short-rib dwarfism is reported and the clinical and radiological differences between this and Majewski type are discussed. The clinical variability related to the lack or presence of polydactyly is underlined, together with the importance of prenatal diagnosis.