Protein-losing gastroenteropathy with facial anomaly and growth retardation: a mild case of Hennekam syndrome

A Multiplex Kindred with Hennekam Syndrome due to Homozygosity for a CCBE1 Mutation that does not Prevent Protein Expression

Collagen and calcium-binding EGF domain-containing protein 1 (CCBE1) bi-allelic mutations have been associated with syndromes of widespread congenital lymphatic dysplasia, including Hennekam Syndrome (HS). HS is characterized by lymphedema, lymphangiectasia, and intellectual disability. CCBE1 encodes a putative extracellular matrix protein but the HS-causing mutations have not been studied biochemically. We report two HS siblings, born to consanguineous parents of Turkish ancestry, whose clinical phenotype also includes protein losing enteropathy, painful relapsing chylous ascites, and hypogammaglobulinemia. We identified by whole exome and Sanger sequencing the homozygous CCBE1 C174Y mutation in both siblings. This mutation had been previously reported in another HS kindred from the Netherlands. In over-expression studies, we found increased intracellular expression of all forms (monomers, dimers, trimers) of the CCBE1 C174Y mutant protein, by Western blot, despite mutant mRNA levels similar to wild-type (WT). In addition, we detected increased secretion of the mutant CCBE1 protein by ELISA. We further found the mutant and WT proteins to be evenly distributed in the cytoplasm, by immunofluorescence and confocal microscopy. Finally, we found a strong decrease of lymphatic vessels, with a corresponding diminished expression of CCBE1, by immunohistochemistry of the patients' intestinal biopsies. In contrast, mucosal blood vessels and muscularis mucosae showed normal CCBE1 staining. Our findings show that the mutant CCBE1 C174Y protein is not loss-of-function by loss-of-expression.

Linkage and sequence analysis indicate that CCBE1 is mutated in recessively inherited generalised lymphatic dysplasia

Generalised lymphatic dysplasia (GLD) is characterised by extensive peripheral lymphoedema with visceral involvement. In some cases, it presents in utero with hydrops fetalis. Autosomal dominant and recessive inheritance has been reported. A large, non-consanguineous family with three affected siblings with generalised lymphatic dysplasia is presented. One child died aged 5 months, one spontaneously miscarried at 17 weeks gestation, and the third has survived with extensive lymphoedema. All three presented with hydrops fetalis. There are seven other siblings who are clinically unaffected. Linkage analysis produced two loci on chromosome 18, covering 22 Mb and containing 150 genes, one of which is CCBE1. A homozygous cysteine to serine change in CCBE1 has been identified in the proband, in a residue that is conserved across species. High density SNP analysis revealed homozygosity (a region of 900 kb) around the locus for CCBE1 in all three affected cases. This indicates a likely ancestral mutation that is common to both parents; an example of a homozygous mutation representing Identity by Descent (IBD) in this pedigree. Recent studies in zebrafish have shown this gene to be required for lymphangiogenesis and venous sprouting and are therefore supportive of our findings. In view of the conserved nature of the cysteine, the nature of the amino acid change, the occurrence of a homozygous region around the locus, the segregation within the family, and the evidence from zebrafish, we propose that this mutation is causative for the generalised lymphatic dysplasia in this family, and may be of relevance in cases of non-immune hydrops fetalis.

Hennekam Syndrome Presentıng Wıth Abdomınal Mass

We report a patient presenting with an abdominal distention and irritiability, who was found to have Hennekam syndrome. A physical examination revealed left sided hemihypertrophy and a mass with undefined margins around the umblical region. Ultrasonography and contrast enhanced computerised tomography revealed a solid heterogeneous mass extending from the parapancreatic region into the mesenteric root and, diagnostic laparotomy was performed. The intestinal walls and the mesentery were found to be diffusely thickened. Histopathological analysis revealed fibrosis along with cystic enlargement of the lymphatic vessels. The patient had left periorbital edema and facial dysmorphism. Non-pitting edema of the abdomen, left arm, left leg, and left labia majora was noted. Laboratory tests showed hypoproteinemia, hypoalbuminemia, and high faecal α-1 anti trypsin. Endoscopic examination revealed milky fluid oozing from the mucosa into the duodenal lumen. Histopathological analysis revealed total villus atrophy and cryptic hyperplasia. We postulate that an enlargement in the intestinal wall could be mistaken for an abdominal mass, and, we present this case of an abdominal mass as a new manifestation of Hennekam syndrome.

Cutaneous manifestations and massive genital involvement in Hennekam syndrome

We describe a 16-year-old boy with intestinal lymphangiectasia, lymphedema of the limbs and genitalia, mild mental retardation, and facial anomalies (Hennekam syndrome) and cutaneous lesions. Severe edema in the genital area created a gigantic mass that included the scrotum and penis. Numerous grouped red-violaceous pseudo-vesicular lesions and plaques, as well as verrucous brown papules, were present on the penis and scrotum. The prepuce was hypertrophic, with severe phimosis. Histologic analysis revealed dilated lymphatic vessels lined by a discontinuous layer of flat endothelial cells in the papillary dermis and extending down to the reticular dermis. Dilated blood vessels were also present but no cellular abnormalities were identified. A diagnosis of superficial cutaneous lymphatic malformations was made. To the best of our knowledge, this is the first detailed cutaneous histologic investigation in a patient with Hennekam syndrome. We assume that the onset of cutaneous lesions in our patient was likely triggered by a generalized worsening of his lymphedema.

Hennekam syndrome presenting as nonimmune hydrops fetalis, congenital chylothorax, and congenital pulmonary lymphangiectasia

We report a female infant with congenital lymphedema, facial anomalies, intestinal lymphangiectasia consistent with a diagnosis of Hennekam syndrome. At birth the patient presented with severe respiratory distress due to nonimmune hydrops fetalis, a congenital chylothorax (CC), and pulmonary lymphangiectasia. Hydrops fetalis may be present in newborns with the Hennekam syndrome. Lymphoscintigraphy can be useful in explaining pleural-pulmonary involvement of this generalized lymph vessel malformation syndrome.

Lymphedema-lymphangiectasia-mental retardation (Hennekam) syndrome: a review

The Hennekam syndrome is an infrequently reported heritable entity characterized by lymphedema, lymphangiectasia, and developmental delay. Here we add an additional 8 patients, and compare their findings to the 16 cases from the literature. The lymphedema is usually congenital, can be markedly asymmetrical, and, often, gradually progressive. Complications such as erysipelas are common. The lymphangiectasias are present in the intestines, but have also been found in the pleura, pericardium, thyroid gland, and kidney. Several patients have demonstrated congenital cardiac and blood vessel anomalies, pointing to a disturbance of angiogenesis in at least some of the patients. Facial features are variable, and are chiefly characterized, in a typical patient, by a flat face, flat and broad nasal bridge, and hypertelorism. Facial features are thought to mirror the extent of intrauterine facial lymphedema, or may be caused by lymphatic obstruction that affects the early migration of neural crest tissue. Other anomalies have included glaucoma, dental anomalies, hearing loss, and renal anomalies. The psychomotor development varies widely, even within a single family, from almost normal development to severe mental retardation. Convulsions are common. The existence of 10 familial cases, equal sex ratio, increased parental consanguinity rate (4/20 families), and absence of vertical transmission are consistent with an autosomal recessive pattern of inheritance. It seems likely that most (but not all) manifestations of the entity can be explained as sequences of impaired prenatal and postnatal lymphatic flow, suggesting that the causative gene(s) should have a major function in lymphangiogenesis.

Severe lymphedema, intestinal lymphangiectasia, seizures and mild mental retardation: further case of Hennekam syndrome with a severe phenotype

We report on an Italian patient affected by severe lymphedema of lower limbs, genitalia and face, intestinal lymphangiectasia, seizures, and moderate mental retardation. He has a flat face, flat nasal bridge, and hypertelorism. We propose that he presents with a severe form of Hennekam syndrome.

Early death in two sisters with Hennekam syndrome

We report on two sisters with facial anomalies, protein-losing enteropathy, and intestinal lymphangiectasia consistent with the diagnosis of Hennekam syndrome. Both patients had a number of other anomalies not previously described in this autosomal recessive disorder, i.e., primary hypothyroidism, hypertrophic pyloric stenosis, and an early fatal outcome. These cases support the autosomal recessive transmission and the expansion of the phenotype of the Hennekam syndrome.

Lymphoscintigraphic manifestations of Hennekam syndrome--a case report

Hennekam syndrome is a rare, recently described genetic disorder in which facial anomalies and mental retardation accompany congenital lymphedema and intestinal lymphangiectasia. Several other somatic abnormalities have variously been described, as have milder degrees of lymphatic dysfunction. The authors herein describe a case of Hennekam syndrome in which the diagnostic difficulties were partially overcome by the judicious use of radionuclide scintigraphy to verify the lymphedematous component of the patient's presentation.

[Hennekam syndrome]

Hennekam syndrome is a disorder comprising intestinal lymphangiectasia, facial anomalies and moderate mental retardation. Eight cases have been previously reported.

CASE REPORT

A 17-month-old girl was admitted to hospital for peripheral edema. On physical examination, she presented with a normal mental development. Facial anomalies were noted including a flat face, depressed and broad nasal bridge, puffy eye lids, mild down-slanting palpebral fissures, hypertelorism, epicanthal folds, bulbous nasal tip, small mouth, and low set ears. A simian line and haemangiomas on the arms, trunk and left limb were also noted. There was no organomegaly. Laboratory investigations showed iron deficiency anemia, hypoproteinemia, hypogammaglobulinemia and an elevated level of alpha-1 antitrypsin excreted in the feces. Endoscopic investigation and the small bowel biopsy showed findings consistent with lymphangiectasia. The patient did well on 24 hour enteral nutrition including medium-chain triglyceride rich diet and infusion of human albumin.

CONCLUSION

We have aimed to remind that Hennekam syndrome should be included in differential diagnosis when intestinal lymphangiectasia are associated with facial anomalies.

Craniosynostosis and kidney malformation in a case of Hennekam syndrome

Hennekam syndrome is a rare autosomal recessive syndrome which was described for the first time in 1989. Here, we present a girl with intestinal lymphangiectasia, severe lymphedema of limbs, seizures, mild mental retardation, and facial anomalies consistent with the diagnosis of Hennekam syndrome. In addition, she had an ectopic kidney and craniosynostosis of the coronal suture, 2 manifestations not previously reported in this syndrome. While the molecular basis of Hennekam syndrome remains, as yet, unknown, this report illustrates its variable clinical expression.