Split-hand/foot malformation 3 resulting from microduplications in 10q24 region in five patients from India

Split-hand/foot malformation (SHFM) is a genetically heterogeneous congenital limb reduction defect characterized by the deficiencies of central rays of the autopod. Tandem duplications at 10q24 locus account for approximately 20% of all SHFM cases. Here, we report five affected individuals from four unrelated Indian families with SHFM3 caused by microduplication of 10q24 locus showing varied clinical presentations. This report substantiates and extends the current understanding of this rare, multifaceted, and complex condition.

Medical findings and congenital anomalies in Vermeer's paintings

The 17th century was a time of scientific discovery in Europe. Leading academic centers provided the general population with an opportunity to view anatomic dissections of human bodies. Rather than portray idealized versions of individuals, Dutch painters were committed to accurately representing their models. This was true for Johannes Vermeer. The 2023 exhibition of Vermeer's paintings at the Rijksmuseum in Amsterdam provided an unprecedented opportunity to observe 28 of his 37 existing paintings simultaneously in person. Here the authors suggest that in at least eight paintings a visibly pregnant woman is present. Vermeer's wife was pregnant or lactating most of the time during their 22-year marriage. Further, evidence of specific medical findings and congenital anomalies such as polydactyly, ectrodactyly, alopecia, kyphosis, and hyperthyroidism were observed in the paintings. These have not been previously reported in the medical or art history literature.

Osteogenesis Imperfecta and Split Foot Malformation due to 7q21.2q21.3 Deletion Including COL1A2, DLX5/6 Genes: Review of the Literature

Copy number variation in loss of 7q21 is a genetic disorder characterized by split hand/foot malformation, hearing loss, developmental delay, myoclonus, dystonia, joint laxity, and psychiatric disorders. Osteogenesis imperfecta caused by whole gene deletions of COL1A2 is a very rare condition. We report a Turkish girl with ectrodactyly, joint laxity, multiple bone fractures, blue sclera, early teeth decay, mild learning disability, and depression. A copy number variant in loss of 4.8 Mb at chromosome 7 (q21.2q21.3) included the 58 genes including DLX5, DLX6, DYNC1I1, SLC25A13, SGCE, and COL1A2 . They were identified by chromosomal microarray analysis. We compared the findings in our patients with those previously reported. This case report highlights the importance of using microarray to identify the genetic etiology in patients with ectrodactyly and osteogenesis imperfecta.

Absent meibomian glands and cone dystrophy in ADULT syndrome: identification by whole exome sequencing of pathogenic variants in two causal genes TP63 and CNGB3

BACKGROUND

Ectrodactyly is a rare congenital limb malformation characterized by a deep median cleft of the hand and/or foot due to the absence of central rays. It could be isolated or depicts a part of diverse syndromic forms. Heterozygous pathogenic variants in the TP63 gene are responsible for at least four rare syndromic human disorders associated with ectrodactyly. Among them, ADULT (Acro-Dermato-Ungual-Lacrimal-Tooth) syndrome is characterized by ectodermal dysplasia, excessive freckling, nail dysplasia, and lacrimal duct obstruction, in addition to ectrodactyly and/or syndactyly. Ophthalmic findings are very common in TP63-related disorders, consisting mainly of lacrimal duct hypoplasia. Absent meibomian glands have also been well documented in EEC3 (Ectrodactyly Ectodermal dysplasia Cleft lip/palate) syndrome but not in ADULT syndrome.

METHODS

We report a case of syndromic ectrodactyly consistent with ADULT syndrome, with an additional ophthalmic manifestation of agenesis of meibomian glands. The proband, as well as her elder sister, presented with congenital cone dystrophy.The molecular investigation was performed in the proband using Whole Exome Sequencing. Family segregation of the identified variants was confirmed by Sanger sequencing.

RESULTS

Two clinically relevant variants were found in the proband: the novel de novo heterozygous missense c.931A > G (p.Ser311Gly) in the TP63 gene classified as pathogenic, and the homozygous nonsense pathogenic c.1810C > T (p.Arg604Ter) in the CNGB3 gene. The same homozygous CNGB3 variation was also found in the sister, explaining the cone dystrophy in both cases.

CONCLUSIONS

Whole Exome Sequencing allowed dual molecular diagnoses: de novo TP63-related syndromic ectrodactyly and familial CNGB3-related congenital cone dystrophy.

Variable clinical presentation of split hand/foot malformation syndrome in a family with microduplication of 10q24.32: a case report

SHFM (Split Hand/Foot Malformation) is a heterogeneous group of disorders characterized by the presence of clefts in the hands and feet, along with syndactyly of the digits. In this article, we describe a family in which two members exhibit characteristic developmental abnormalities associated with SHFM, presenting with variable clinical features. Using whole-genome sequencing, we identified a microduplication of a chromosomal segment on locus 10q24.32, specifically spanning positions 102934495 to 103496555, encompassing genes BTRC, POLL, FBXW4 and LBX1 in the proband. Genomic duplications, including these genes, were previously described in patients diagnosed with the third type of SHFM. We validated the presence of this structural rearrangement in 7 family members, including the proband and the proband's father. Remarkably, further investigation demonstrated that the detected duplication exhibits a mosaic state in the phenotypically normal paternal grandmother of the proband, thereby providing a plausible explanation for the absence of a pathological phenotype in her.

[Ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome]

The ectrodactyly-ectodermal dysplasia-clefting syndrome is an extremely rare genetic disorder that is inherited as an autosomal dominant trait, but can also occur sporadically. It is characterized by the triad of ectrodactyly (absence of fingers), ectodermal dysplasia and cleft lip and palate along with variable involvement of other organs. Both the ectodermal and mesodermal tissues may be affected resulting in a spectrum of phenotypes. Early diagnosis and treatment signify a unique challenge for those involved in the clinical management, while enable counseling and preparation of parents for the tasks ahead of them. In our report, we describe the case of a patient with sporadic EEC syndrome. In addition to the presentation of the complex phenotype along with the medical interventions, we summarize the most important characteristics of the disease, the diagnostic and therapeutic possibilities as well as the clinical significance of the accurate genetic verification. Using whole exome sequencing, we identified in the 3q28 chromosomal region a pathogenic mutation within the TP63 gene previously linked to the EEC3 phenotypes. The knowledge of pathogenic mutation provides the means to prenatal diagnostics or in vitro fertilization methods that allows us to minimize the possibility of inheriting the syndrome in the patient's offspring. By presenting our case, we aim to draw attention to this rare and disabling disease that requires the high quality works of a multidisciplinary team capable of ensuring good quality of life for the patient. Orv Hetil. 2023; 164(46): 1831-1837.

A genotype-phenotype correlation in split-hand/foot malformation type 1: further refinement of the phenotypic subregions within the 7q21.3 locus

Background: Split-hand/foot malformation type 1 (SHFM1) refers to the group of rare congenital limb disorders defined by the absence or hypoplasia of the central rays of the autopods with or without accompanying anomalies, such as hearing loss, craniofacial malformation, and ectodermal dysplasia. Consequently, the condition is characterized by clinical variability that hinders diagnostic and counseling procedures. SHFM1 is caused by pathogenic variants affecting the DLX5/6 genes and/or their tissue-specific enhancers at the 7q21.3 locus. Herein, we report on seven patients from five unrelated Polish families affected by variable symptoms of the SHFM1 spectrum, all harboring 7q21.3 or 7q21.2-q21.3 rearrangements, and provide a genotype-phenotype correlation in the studied cohort. Methods: We applied GTG banding, array-based comparative genomic hybridization (aCGH), and whole-genome sequencing (WGS) in order to identify the causative aberrations in all affected patients. Results: The identified pathogenic structural variants included deletions and/or translocations involving the 7q21.3 locus, i.e., t(7;10)(q21.3;q22.2) and t(7;12)(q21.3;q21.2) in all affected individuals. Interestingly, a sporadic carrier of the latter aberration presented the SHFM1 phenotype with additional features overlapping with Baker-Gordon syndrome (BAGOS), which resulted from the translocation breakpoint at chromosome 12 within the SYT1 gene. Conclusion: Clinical variability of the studied cohort reflects the composition of the DLX5/6 regulatory elements that were dislocated from their target genes by chromosomal rearrangements. The correlation of our data with the previously published observations enabled us to update the phenotypic subregions and regulatory units within the SHFM1 locus. In addition, we present the first case of SHFM1 and BAGOS-like phenotype that resulted from translocation breakpoints at chromosomes 7 and 12, both of which were pathogenic, and consequently, we show the first evidence that BAGOS can also result from the regulatory loss-of-function SYT1 mutations. In this paper, we emphasize the utility of sequence-based approaches in molecular diagnostics of disorders caused by regulatory structural variants.

Prenatal prospective ultrasound diagnosis

OBJECTIVE

Prenatal diagnosis of the Ectrodactyly-Ectodermal dysplasia-clefting (EEC) syndrome has been based upon the detection of ectrodactyly, in association with facial clefting and/or positive family history. Our aim is to describe other ultrasonographic features indicating the presuntive diagnosis, regardless of genetic diagnosis, especially in cases of negative family history.

MATERIALS AND METHODS

A case report and a review of the literature was assessed.

RESULTS

Our case report showed a singleton foetus "lobster claw" deformities of hands and feet. Paternal history revealed bilateral agenesia of two fingers. Through literature, 15 case reports of prenatal diagnosis of EEC syndrome were found, 14 of which were eligible for our systematic review. The 33% of cases (5/15) had a familiar history of EEC, thus, we found one case of consanguinity of parents. Anomalies EEC-related were recognized in the 40% of cases (6/15). An association with genitourinary anomalies was found in 30% (5/15) of them.

CONCLUSIONS

A strong suspicion of final diagnosis of EEC may be done in the presence of ectrodactyly, facial clefting and urinary malformation especially in cases of negative family history. More attention should be given to a genetic counseling, especially to understand a possible relation to other genetic syndromes.

Split Hand-Foot and Deafness in a Patient with 7q21.13-q21.3 Deletion Not Including the DLX5/6 Genes

Split Hand-Foot Malformation (SHFM) is a congenital limb defect characterized by a median cleft of the hands and/or feet due to the absence/hypoplasia of the central rays. It may occur as part of a syndromic condition or as an isolated malformation. The most common of the six genetic loci identified for this condition is correlated to SHFM1 and maps in the 7q21q22 region. SHFM1 is characterized by autosomal dominant transmission, incomplete penetrance and variable expressivity. Associated features often include hearing loss, intellectual disability/developmental delay and craniofacial abnormalities. Disruption of the DLX5/DLX6 genes, mapping within the SHFM1 locus, is now known to be responsible for the phenotype. Through SNP array, we analyzed a patient affected by SHFM1 associated with deafness and an abnormality of the inner ear (incomplete partition type I); we identified a deletion in 7q21, not involving the DLX5/6 genes, but including exons 15 and 17 of DYNC1I1, known to act as exonic enhancers (eExons) of the DLX5/6 genes. We further demonstrated the role of DYNC1I1 eExons in regulating DLX5/6 expression by means of showing a reduced expression of the DLX5/6 genes through RT-PCR in a patient-derived lymphoblastoid cell line. Furthermore, our data and a review of published cases do not support the hypothesis that DLX5/6 are imprinted in humans. This work is an example of how the disruption of regulatory elements can be responsible for congenital malformations.

Gollop-Wolfgang Complex: Clinical and Imaging Implications

Gollop-Wolfgang complex is defined as the presence of a distal bifid femur and tibial hemimelia with or without hand ectrodactyly. The condition commonly presents with several skeletal abnormalities and internal organ congenital defects. We hereby report a case with a classical presentation of Gollop-Wolfgang complex.

From the Luttrell Psalter to the Lobster Boy: Split hand and foot awaken many facets of human nature

A marginal illustration of a non-ambulatory child in the 14th Century Luttrell Psalter is the earliest currently identifiable image of an individual with Split Hand Split Foot with Long Bone Deficiency (SHFLD). Changes in portrayal of SHFLD over the centuries reflect changes in social perception of disabilities from pious sympathy to scientific curiosity and unfortunately also morbid fascination. Hopefully understanding of the past attitudes toward split hand and foot as reflected in art can help in moving toward acceptance of individuals with this highly visible malformation.

EEC-LM-ADULT syndrome caused by R319H mutation in TP63 with ectrodactyly, syndactyly, and teeth anomaly: A case report

RATIONALE

Ectrodactyly ectodermal dysplasia-cleft lip/palate (EEC) syndrome, limb-mammary syndrome (LMS), and acro-dermato-ungual-lacrimal-tooth (ADULT) syndrome are caused by a TP63 gene disorder and have similar features. In the present article, a R319H mutation in TP63 is reported, and the correlation between genotype and phenotype is discussed based on the current case and previous literature.

PATIENT CONCERNS

A 13-year-old Japanese boy had ectrodactyly in the right hand and left foot and syndactyly in the left and right foot, and tooth shape abnormalities.

DIAGNOSES

Peripheral blood samples were obtained, and mutation analysis was performed. A heterozygous G>A transition at cDNA position 956 of the TP63 gene was found. The patient was diagnosed with ELA (EEC/LM/ADULT) syndrome based on his clinical features and mutation analysis results.

INTERVENTIONS

The patient underwent surgery to correct the left foot malformation at 1 year of age and the right foot syndactyly at 11 years of age.

OUTCOMES

No complications were observed after the first and second operations. He can walk comfortably after them, and no additional interventions will be planned in him. We continued to follow up with him up to the present.

LESSONS

The concept of ELA syndrome, which is the original concept of combining 3 syndromes (EEC syndrome/LMS/ADULT syndrome) into a unique clinical entity, can help clinicians to better understand TP63-related syndromes and improve the differential diagnosis of these syndromes.

Prenatal diagnosis of Klippel-Trenaunay syndrome: Series of four cases and review of the literature

Klippel-Trenaunay syndrome is a rare disease with a classic triad of port wine stains, varicose veins, and bony and soft tissue hypertrophy of an extremity. The quality of life in these patients is significantly affected, making the prenatal diagnosis of Klippel-Trenaunay syndrome important. We present four prenatally diagnosed cases of this anomaly with a unique case of ectrodactyly of the hand in foetus with Klippel-Trenaunay syndrome. Such a combination has not been previously reported prenatally. A review of the literature for similar cases is also presented.

Surgical Ectrodactyly Repair Using Limb-lengthening and Bone Tissue Engineering Techniques in a Toy Dog Breed

BACKGROUND/AIM

Bone tissue engineering is an emerging field of regenerative medicine that holds promise for the restoration of bones affected by trauma, neoplastic diseases, and congenital deformity. During the past decade, bone tissue engineering has evolved from the use of biomaterials that can only replace small areas of damaged bone, to the use of scaffolds in which grafts can be seeded before implantation. This case report proposes an alternative option for a veterinary patient suffering from ectrodactyly, which is one of several congenital deformities in dogs. A 2-month-old male toy poodle dog with ectrodactyly was treated using several stages of surgery involving pancarpal arthrodesis, limb lengthening, and bone tissue engineering techniques.

RESULTS AND CONCLUSION

Over a period of 2 years, the operated limb gained almost the same function as the contralateral limb. Bone tissue engineering techniques can be used for the treatment of congenital deformities in dogs.

WNT10B variants in split hand/foot malformation: Report of three novel families and review of the literature

Split-hand/foot malformation (SHFM) is a genetically heterogeneous congenital limb malformation typically limited to a defect of the central rays of the autopod, presenting as a median cleft of hands and feet. It can be associated with long bone deficiency or included in more complex syndromes. Among the numerous genetic causes, WNT10B homozygous variants have been recently identified in consanguineous families, but remain still rarely described (SHFM6; MIM225300). We report on three novel SHFM families harboring WNT10B variants and review the literature, allowing us to highlight some clinical findings. The feet are more severely affected than the hands and there is a frequent asymmetry without obvious side-bias. Syndactyly of third-fourth fingers was a frequent finding (62%). Polydactyly, which was classically described in SHFM6, was only present in 27% of patients. No genotype-phenotype correlation is delineated but heterozygous individuals might have mild features of SHFM, suggesting a dose-effect of the WNT10B loss-of-function.

Genetic regulatory pathways of split-hand/foot malformation

Split-hand/foot malformation (SHFM) is caused by mutations in TP63, DLX5, DLX6, FGF8, FGFR1, WNT10B, and BHLHA9. The clinical features of SHFM caused by mutations of these genes are not distinguishable. This implies that in normal situations these SHFM-associated genes share an underlying regulatory pathway that is involved in the development of the central parts of the hands and feet. The mutations in SHFM-related genes lead to dysregulation of Fgf8 in the central portion of the apical ectodermal ridge (AER) and subsequently lead to misexpression of a number of downstream target genes, failure of stratification of the AER, and thus SHFM. Syndactyly of the remaining digits is most likely the effects of dysregulation of Fgf-Bmp-Msx signaling on apoptotic cell death. Loss of digit identity in SHFM is hypothesized to be the effects of misexpression of HOX genes, abnormal SHH gradient, or the loss of balance between GLI3A and GLI3R. Disruption of canonical and non-canonical Wnt signaling is involved in the pathogenesis of SHFM. Whatever the causative genes of SHFM are, the mutations seem to lead to dysregulation of Fgf8 in AER cells of the central parts of the hands and feet and disruption of Wnt-Bmp-Fgf signaling pathways in AER.

Non-syndromic bilateral ulnar aplasia with humero-radial synostosis and oligo-ectro-dactyly

Congenital anomalies of the upper limbs are rare and etiologically heterogeneous. Herein, we report a male infant with non-syndromic bilateral Type Vb ulnar longitudinal dysplasia with radiohumeral synostosis (apparent humeral bifurcation), and bilateral oligo-ectro-syndactyly who was born following an uncomplicated pregnancy, with no maternal use of prescription or illicit medication. Array CGH (60,000 probes) and chromosomal breakage analysis (DEB) were normal. Similar appearances have been reported in children exposed to thalidomide or cocaine, but sporadic patients have also been reported without a prior history of exposure to known teratogens.

De novo IGF2 mutation on the paternal allele in a patient with Silver-Russell syndrome and ectrodactyly

Although paternally expressed IGF2 is known to play a critical role in placental and body growth, only a single mutation has been found in IGF2. We identified, through whole-exome sequencing, a de novo IGF2 indel mutation leading to frameshift (NM_000612.5:c.110_117delinsAGGTAA, p.(Leu37Glnfs*31)) in a patient with Silver-Russell syndrome, ectrodactyly, undermasculinized genitalia, developmental delay, and placental hypoplasia. Furthermore, we demonstrated that the mutation resided on the paternal allele by sequencing the long PCR product harboring the mutation- and methylation-sensitive SmaI and SalI sites before and after SmaI/SalI digestion. The results, together with the previous findings in four cases from a single family with a paternally inherited IGF2 nonsense mutation and those in patients with variable H19 differentially methylated region epimutations leading to compromised IGF2 expression, suggest that the whole phenotype of this patient is explainable by the IGF2 mutation, and that phenotypic severity is primarily determined by the IGF2 expression level in target tissues.

Focal Dermal Hypoplasia with a De novo Mutation p.E300* of PORCN Gene in a Male Infant

Focal dermal hypoplasia is a rare disorder inherited in an X-linked dominant pattern and is usually antenatally lethal in males. We report a surviving male with postzygotic de novo mutation p.E300* in exon 10 of PORCN gene with mosaicism, earlier reported in a female of Thai origin. This is the first report of this mutation from the Indian subcontinent.

Split-hand/feet malformation: A rare syndrome

Split-hand/split-foot malformation (SHFM) is mainly inherited as an autosomal dominant trait with incomplete penetrance and characterized by malformation of the limb involving the central rays of the autopod. It presents with a deep median cleft of the hand and/or foot, aplasia/hypoplasia of the phalanges, metacarpals, and metatarsals. Pathogenic mechanism is a failure to maintain signaling from the median apical ectodermal ridge. Without this signaling, cells of the underlying progress zone stop proliferation and differentiation which in turn results in defects of the central rays. We describe a case of SHFM in 10-year-old boy.

Ectrodactyly and Lethal Pulmonary Acinar Dysplasia Associated with Homozygous FGFR2 Mutations Identified by Exome Sequencing

Ectrodactyly/split hand-foot malformation is genetically heterogeneous with more than 100 syndromic associations. Acinar dysplasia is a rare congenital lung lesion of unknown etiology, which is frequently lethal postnatally. To date, there have been no reports of combinations of these two phenotypes. Here, we present an infant from a consanguineous union with both ectrodactyly and autopsy confirmed acinar dysplasia. SNP array and whole-exome sequencing analyses of the affected infant identified a novel homozygous Fibroblast Growth Factor Receptor 2 (FGFR2) missense mutation (p.R255Q) in the IgIII domain (D3). Expression studies of Fgfr2 in development show localization to the affected limbs and organs. Molecular modeling and genetic and functional assays support that this mutation is at least a partial loss-of-function mutation, and contributes to ectrodactyly and acinar dysplasia only in homozygosity, unlike previously reported heterozygous activating FGFR2 mutations that cause Crouzon, Apert, and Pfeiffer syndromes. This is the first report of mutations in a human disease with ectrodactyly with pulmonary acinar dysplasia and, as such, homozygous loss-of-function FGFR2 mutations represent a unique syndrome.

Possible association between acetazolamide administration during pregnancy and multiple congenital malformations

Congenital malformations might occur because of environmental or genetic factors, and sometimes occur because of unknown causes. Acetazolamide is a carbonic anhydrase inhibitor that is used to treat idiopathic intracranial hypertension, glaucoma, and epilepsy. The use of acetazolamide has not been recommended for pregnant women because of reported teratogenic risks. Congenital malformations, such as ectrodactyly, syndactyly, cleft lip/palate, and retarded incisor teeth development, have been reported in experimental animals. However, tooth agenesis due to the use of acetazolamide has not been reported yet. Oligodontia is a severe type of tooth agenesis involving six or more congenitally missing teeth. The causes of oligodontia are attributed to environmental factors, such as irradiation, drugs, trauma, tumors, infection, genetic factors, or a combination. There is no credible evidence of undesirable effects of acetazolamide use in human pregnancy. However, we report a case of a 12-year-old Saudi boy who was exposed to maternal acetazolamide (1,000 mg/day) for treatment of idiopathic intracranial hypertension before pregnancy, during the first trimester, and throughout the pregnancy. This treatment might have resulted in some congenital malformations, such as ectrodactyly, syndactyly, and oligodontia.

Prenatal Diagnosis of Ectrodactyly in the First Trimester by Three-Dimensional Ultrasonography

Introduction Ectrodactyly, also known as split hand/foot malformation, is a rare developmental abnormality of the limbs that consists of absent central digits, a deep median cleft, and fusion of the remaining lateral digits, ultimately producing clawlike extremities. This case represents one of the earliest reported diagnoses of this anomaly to utilize three-dimensional (3D) ultrasonography. Case A nulliparous woman presented at 13 weeks of gestation for first-trimester aneuploidy screening. On two-dimensional (2D) imaging, she was noted to have a fetus with a shortened right upper limb and a malformed right hand with no clearly visualized digits. The anomaly was then further evaluated with both transabdominal and transvaginal 2D and 3D ultrasonography with postprocessing visualization, revealing absent central digits. Neither the patient nor her husband reported any personal or family history of skeletal or other structural malformations. Discussion Fetal limb abnormalities are being encountered at increasingly earlier gestational ages due to improvements in image quality and expanded use of ultrasound in the first trimester. Early identification of fetal limb malformations without a definitive diagnosis or a clear pattern of inheritance can present a challenging clinical scenario. Patients may opt for earlier termination of pregnancy rather than wait for additional information to guide decision-making.

Asymptomatic Congenital Absence of Lateral Pedal Rays

Complete absence of 1 or more pedal rays is a rare condition. In the present report, the case of an adult male with complete congenital absence of his right fourth and fifth pedal rays is described. The condition had been asymptomatic until he had sustained an acute third metatarsal fracture and was satisfactorily treated with cast immobilization.

Goltz syndrome: a newborn with ectrodactyly and skin lesions

Goltz syndrome or Focal Dermal Hypoplasia is a rare multisystem disorder, involving all the three germ cell layers. The disease is thought to be inherited in X-linked dominant fashion with heterogeneous mutations of the PORCN gene at Xp11.23 locus. Majority of the cases are sporadic, mainly due to postzygotic somatic mutations. The clinical spectrum includes characteristic cutaneous manifestations, multiple skeletal anomalies, and involvement of the eyes, hair, nails, kidneys, and so on. Considerable variability is noted in the clinical expression of the disease probably due to genomic mosaicism. Around 300 cases of Goltz syndrome have been reported in the literature. Here, we report such a case with characteristic skin lesions, multiple bony defects, distinctive facial features, coloboma of iris, and bilateral hydronephrosis. The diagnosis was evident immediately after birth due to the characteristic clinical picture of the baby.

Focal Dermal Hypoplasia Due to De Novo Mutation c.1061T>C(p.Leu354Pro) in the PORCN Gene: Importance of Early Diagnosis and Multidisciplinary Follow-Up

Focal dermal hypoplasia (FDH) is a rare multisystem disorder characterized by abnormalities in tissues derived from the meso-ectoderm, mainly affecting the skin, eyes, teeth and skeleton. We present the case of a young girl with FDH due to de novo mutation c.1061T>C (p.Leu354Pro) in the PORCN gene, responsible for defects in bone, eyes, skeleton, heart, maxillary and anus/rectum malformation. At birth, an infectious etiology and cutaneous syndromes that produce similar skin lesions were ruled out. Clinical manifestations led to the diagnosis of FDH, subsequently confirmed by genetic studies during the neonatal period. Early diagnosis allows organizing a detailed and personalized follow-up, which makes interventions more effective. This has contributed to satisfactory development to date in our patient. These patients present a host of possible complications requiring the coordinated effort of a multidisciplinary medical team from the start, all coordinated by a pediatrician.

Heterozygous DLX5 nonsense mutation associated with isolated split-hand/foot malformation with reduced penetrance and variable expressivity in two unrelated families

BACKGROUND

Split-hand/foot malformation (SHFM) is a clinically and genetically heterogeneous limb abnormality characterized by the absence or hypoplasia of the central rays of the autopod. SHFM1, which is one out of seven known SHFM loci, maps to 7q21.2-q21.3. SHFM1 is usually inherited as an autosomal dominant trait with reduced penetrance, although recessive inheritance has been described for a single family carrying a homozygous DLX5 missense variant. In most cases, SHFM1 results from heterozygous deletions encompassing DLX5/DLX6 genes or from inversions and translocations separating the genes from their limb specific enhancers. Recently, a single Chinese family with dominant SHFM1 was shown to result from a heterozygous DLX5 missense mutation.

METHODS

In this study, we report on four male individuals from two unrelated Polish families (one sporadic and one familial case) presenting with isolated SHFM. We tested both probands for known molecular causes of SHFM, including TP63, WNT10B, DLX5 mutations and copy number changes using 1.4 M array CGH.

RESULTS

Sanger sequencing of DLX5 revealed a novel heterozygous nonsense mutation c.G115T(p.E39X) in both index patients. Segregation studies demonstrated that the variant was present in all affected family members but also in three apparently healthy relatives (two females and one male).

CONCLUSION

This is the first report of a heterozygous DLX5 nonsense mutation resulting in incompletely penetrant autosomal dominant isolated SHFM1. Data shown here provides further evidence for the contribution of DLX5 point mutations to the development of ectrodactyly and suggest the possibility of sex-related segregation distortion with an excess of affected males.

Split-hand/feet malformation in three tamilian families and review of the reports from India

Split-hand/foot malformation (SHFM) is a rare condition which can be either syndromic or nonsyndromic. We report three unrelated pedigrees, one with autosomal dominant (AD) inheritance and the other two with autosomal recessive (AR) pattern. We also briefly review the published reports from India.

Clinical, genetic, and molecular aspects of split-hand/foot malformation: an update

We here provide an update on the clinical, genetic, and molecular aspects of split-hand/foot malformation (SHFM). This rare condition, affecting 1 in 8,500-25,000 newborns, is extremely complex because of its variability in clinical presentation, irregularities in its inheritance pattern, and the heterogeneity of molecular genetic alterations that can be found in affected individuals. Both syndromal and nonsyndromal forms are reviewed and the major molecular genetic alterations thus far reported in association with SHFM are discussed. This updated overview should be helpful for clinicians in their efforts to make an appropriate clinical and genetic diagnosis, provide an accurate recurrence risk assessment, and formulate a management plan.

Split hand/foot malformation with long-bone deficiency and BHLHA9 duplication: report of 13 new families

Split hand/foot malformation (SHFM) with long-bone deficiency (SHFLD, MIM#119100) is a rare condition characterized by SHFM associated with long-bone malformation usually involving the tibia. Previous published data reported several unrelated patients with 17p13.3 duplication and SHFLD. Recently, the minimal critical region had been reduced, suggesting that BHLHA9 copy number gains are associated with this limb defect. Here, we report on 13 new families presenting with ectrodactyly and harboring a BHLHA9 duplication.

Ectrodactyly, ectodermal dysplasia, cleft lip, and palate (EEC syndrome)

The ectodermal dysplasias (EDs) are a large and complex group of diseases. More than 170 different clinical conditions have been recognized and defined as ectodermal dysplasias. Commonly involved ectodermal-derived structures are hair, teeth, nails, and sweat glands. In some conditions, it may be associated with mental retardation. We report a case of 10-year-old male child with ectrodactyly, syndactyly, ED, cleft lip/palate, hearing loss, and mental retardation.

Prenatal Diagnosis of EEC Syndrome with "Lobster Claw" Anomaly by 3D Ultrasound

THE EEC SYNDROME IS A GENETIC ANOMALY CHARACTERIZED BY THE TRIAD: ectodermal dysplasia (development of anomalies of the structures derived from the embryonic ectodermal layer), ectrodactyly (extremities, hands and feet malformations) and cleft lip and/or palate; these malformations can be seen together or in isolation. The prenatal diagnosis can be made by two-dimensional ultrasonography (2DUS) that identifies the facial and/or limb anomalies, most characteristic being the "lobster-claw" hands. The three-dimensional ultrasonography (3DUS) provides a better analysis of the malformations than the 2DUS. A 25-year-old primigravida, had her first transvaginal ultrasonography that showed an unique fetus with crow-rump length of 47 mm with poorly defined hands and feet,. She was suspected of having sporadic form of EEC syndrome. The 2DUS performed at 19 weeks confirmed the EEC syndrome, showing a fetus with lobster-claw hands (absence of the 2(nd) and 3(rd) fingers), left foot with the absence of the 3rd toe and the right foot with syndactyly, and presence of cleft lip/palate. The 3DUS defined the anomalies much better than 2DUS including the lobster-claw hands.

Ectrodactyly, ectodermal dysplasia, and cleft lip/palate syndrome: A case report of "Incomplete syndrome"

Ectrodactyly, ectodermal dysplasia, and cleft lip/palate (EEC) is a rare syndrome having ectrodactyly, ectodermal dysplasia, and cleft lip/palate. So far, very few cases have been reported in literature. However, we report a case of incomplete EEC syndrome having ectrodactyly and cleft lip and palate with absence of signs of ectodermal dysplasia with no other systemic anomalies. Other feature noted is the syndactyly of toes which is reported rarely in this syndrome. A multidisciplinary approach for treatment is needed which is co-ordinated by pedodontist or pediatrician.

Familial clustering of a rare syndrome

Ectrodactyly, ectodermal dysplasia and cleft palate syndrome is a rare autosomal dominant multiple congenital anomaly syndrome with variable expressivity and reduced penetration. The cardinal features are cleft palate/lip, lobster hand deformity, sparse hypopigmented hair, dry scaly skin, and lacrimal and urogenital anomalies. A neonate presented to us with typical features, his mother and other two siblings were also affected.

Holoprosencephaly and ectrodactyly: Report of three new patients and review of the literature

Holoprosencephaly (HPE) and ectrodactyly represent congenital malformations of the developing forebrain and developing digits, respectively. The combination of these conditions is rare, with only 15 cases known to date (12 previously reported, and 3 new cases described here). While the findings in these patients overlap with previously described genetic conditions, the similarity in phenotypes among these patients has led to the establishment of a at least one distinct syndrome: HPE, ectrodactyly, and bilateral cleft lip-palate syndrome (OMIM 300571). There has been great interest in identifying a genetic cause for the findings in patients with HPE and ectrodactyly; however the cause(s) of this rare association still remain unknown.

Genetically regulated epigenetic transcriptional activation of retrotransposon insertion confers mouse dactylaplasia phenotype

Dactylaplasia, characterized by missing central digital rays, is an inherited mouse limb malformation that depends on two genetic loci. The first locus, Dac, is an insertional mutation around the dactylin gene that is inherited as a semidominant trait. The second locus is an unlinked modifier, mdac/Mdac, that is polymorphic among inbred strains. Mdac dominantly suppresses the dactylaplasia phenotype in mice carrying Dac. However, little is known about either locus or the nature of their interaction. Here we show that Dac is a LTR retrotransposon insertion caused by the type D mouse endogenous provirus element (MusD). This insertion exhibits different epigenetic states and spatiotemporally expresses depending on the mdac/Mdac modifier background. In dactylaplasia mutants (Dac/+ mdac/mdac), the LTRs of the insertion contained unmethylated CpGs and active chromatin. Furthermore, MusD elements expressed ectopically at the apical ectodermal ridge of limb buds, accompanying the dactylaplasia phenotype. On the other hand, in Dac mutants carrying Mdac (Dac/+ Mdac/mdac), the 5' LTR of the insertion was heavily methylated and enriched with inactive chromatin, correlating with inhibition of the dactylaplasia phenotype. Ectopic expression was not observed in the presence of Mdac, which we refined to a 9.4-Mb region on mouse chromosome 13. We report a pathogenic mutation caused by MusD. Our findings indicate that ectopic expression from the MusD insertion correlates with the dactylaplasia phenotype and that Mdac acts as a defensive factor to protect the host genome from pathogenic MusD insertions.