Prenatal diagnosis of Milroy's primary congenital lymphedema

Case report of generalized lymphatic dysplasia with PIEZO1 mutation and review of the literature

Background

The newborn malformation of primary lymphatic dysplasia (PLD), developed primarily due to PIEZO1 gene autosomal recessive mutation, is known to hinder with the lymphatic system action, causing chyle or lymph effusion into the peritoneal cavity or pleura.

Case presentation

A 4-years-old male subject presented with a recurrent chylothorax and bilateral lower limb edema that started at age of 6 months. Lymphoscintigraphy showed lymphangiectasia with chylothorax. The whole exome sequence consisted of Pathogenic variants in PIEZO1 gene associated with lymphatic malformation type 6 (LMPHM6).

Conclusion

This is the first reported pediatric case of PIEZO1 gene mutation in Saudi Arabia. This case highlighted the wide differential diagnosis of recurrent chylothorax and lower limb edema, as well as the relative literature on the molecular foundation, clinical scale, pathophysiology, and lymphatic malformation treatment. patients can be improved via application of standardized chylothorax and lymphedema therapies. Overall, awareness of the diseases related to the thoracic lymphatic circulation should be observed as its prognosis may highly promote better approaches for its management.

Two novel variations p.(Ser1275Thr) and p.(Ser1275Arg) in FLT4 causing prenatal hereditary lymphedema type 1

BACKGROUND

Hereditary lymphedema 1 is a rare congenital condition, characterized by the development of chronic swelling in body parts. It is highly variable in expression and age of onset with different presentations: from feet edema to hydrops fetalis. This affection is genetically heterogeneous with autosomal dominant inheritance and incomplete penetrance due to a mutation in the FLT4 gene in most cases.

CASES

In our study, we report on two fetuses harboring congenital lymphedema with FLT4 variation and review the prenatal confirmed ones of the literatures. Our cases were selected within fetuses explored by exome sequencing in a diagnosis setting. Prenatal ultrasonography showed hydrops fetalis in one case and an increased nuchal translucency with hydrothorax in the other. Comparative genomic hybridization array on amniocentesis was normal in both cases. Exome sequencing identified a variation p.(Ser1275Thr) and p.(Ser1275Arg) in fetus 1 and fetus 2 in the FLT4 gene, respectively. A de novo mutation at the same codon was reported in prenatal literature suggesting possible genotype phenotype correlation.

CONCLUSION

Cystic hygroma/hydrops fetalis are possible manifestations of several disorders. This study illustrates how the integration of exome sequencing in prenatal clinical practice can facilitate the diagnosis and genetic counseling of heterogeneous developmental affections.

Primary lymphedema French National Diagnosis and Care Protocol (PNDS; Protocole National de Diagnostic et de Soins)

Primary lymphedema is a rare chronic pathology associated with constitutional abnormalities of the lymphatic system. The objective of this French National Diagnosis and Care Protocol (Protocole National de Diagnostic et de Soins; PNDS), based on a critical literature review and multidisciplinary expert consensus, is to provide health professionals with an explanation of the optimal management and care of patients with primary lymphedema. This PNDS, written by consultants at the French National Referral Center for Primary Lymphedema, was published in 2019 (https://has-sante.fr/upload/docs/application/pdf/2019-02/pnds_lymphoedeme_primaire_final_has.pdf). Primary lymphedema can be isolated or syndromic (whose manifestations are more complex with a group of symptoms) and mainly affects the lower limbs, or, much more rarely, upper limbs or external genitalia. Women are more frequently affected than men, preferentially young. The diagnosis is clinical, associating mild or non-pitting edema and skin thickening, as confirmed by the Stemmer’s sign (impossibility to pinch the skin on the dorsal side or the base of the second toe), which is pathognomonic of lymphedema. Limb lymphoscintigraphy is useful to confirm the diagnosis. Other causes of swelling or edema of the lower limbs must be ruled out, such as lipedema. The main acute lymphedema complication is cellulitis (erysipelas). Functional and psychological repercussions can be major, deteriorating the patient’s quality of life. Treatment aims to prevent those complications, reduce the volume with low-stretch bandages, then stabilize it over the long term by exercises and wearing a compression garment. Patient education (or parents of a child) is essential to improve observance.

Cystic Hygroma: A Preliminary Genetic Study and a Short Review from the Literature

BACKGROUND

The objective of this study is to examine the hypothesis that cystic hygroma (CH) with normal karyotype can manifest as a Mendelian inherited trait, and that a genetic similitude with hereditary lymphedema exists. To reach this goal, we investigated the prevalence of genetic variants in angiogenesis and lymphangiogenesis genes in a cohort of euploid fetuses with CH that almost resolved before delivery. A short review of cases from literature is also reported.

METHODS AND RESULTS

Five fetuses were screened using a next-generation sequencing approach by targeting 33 genes known to be associated with vascular and lymphatic malformations. The genetic evaluation revealed two novel variants in KDR and KRIT1 genes.

CONCLUSION

A review of the literature to date revealed that an association exists between CH and hereditary lymphedema and, similar to lymphedema, CH can be inherited in autosomal recessive and autosomal dominant manner, with the latter most likely associated with a better prognosis. About KDR and KRIT1 genes, no other similar associations are reported in the literature and caution is needed in their interpretation. In conclusion, we thought that a genetic test for the outcome of familial CH could be of enormous prognostic value.

[Primary lymphedema in childhood]

Lymphedema results from impaired lymphatic transport with increased limb volume and is divided into primary and secondary forms. In children, primary lymphedema is the most frequent, with a sporadic, rarely familial form or associated with complex malformative or genetic disorders. Diagnosis of lymphedema is mainly clinical and lymphoscintigraphy is useful to assess the lymphatic function of both limbs precisely. The main differential diagnosis is overgrowth syndrome. Erysipelas (cellulitis) is the main complication, but psychological or functional discomfort may occur throughout the course of lymphedema. Lymphedema management is based on multilayer low-stretch bandage, skin care, and eventually manual lymph drainage. The objective of treatment is to reduce lymphedema volume and then stabilize it. Multilayer low-stretch bandage and elastic compression are the cornerstone of treatment. Parent's motivation, including self-management, is required to ensure the child's compliance and improve quality of life.

Lymphedema in a 7-year-old boy infected with Wuchereria bancrofti in Sierra Leone: a case report

We present a case of congenital lymphedema in a 7-year-old boy in Sierra Leone with active filarial infection and penile edema. The genital edema with onset at 6 months of age may have been due to a congenital abnormality in lymphatic drainage. Other possible causes of childhood lymphedema, including Milroy's disease, are discussed.

Primary Congenital Lymphedema Complicated by Hydrops Fetalis: A Case Report and Review of the Literature

Introduction. Primary congenital lymphedema is a rare disorder associated with insufficient development of lymphatic vessels. Usually most patients present with lower extremity edema seen sonographically. Rarely primary congenital lymphedema may be associated with severe lymphatic dysfunction resulting in hydrops fetalis. Case. A 27-year-old primigravida with a family history of leg swelling throughout multiple generations was diagnosed early in the third trimester with hydrops fetalis. Delivery was undertaken at 32 weeks for nonreassuring fetal status and the infant expired at approximately 45 minutes of life. Primary congenital lymphedema was confirmed via molecular testing of the vascular endothelial growth factor receptor-3 gene. Discussion. The diagnosis of PCL is suspected prenatally when ultrasound findings coincide with a positive family history of chronic lower limb lymphedema. Isolated PCL is rarely associated with significant complications. Rarely, however, widespread lymphatic dysplasia may occur, possibly resulting in nonimmune hydrops fetalis.

Lymphatic dysfunction, not aplasia, underlies Milroy disease

OBJECTIVE

Milroy disease is an inherited autosomal dominant lymphoedema caused by mutations in the gene for vascular endothelial growth factor receptor-3 (VEGFR-3, also known as FLT4). The phenotype has to date been ascribed to lymphatic aplasia. We further investigated the structural and functional defects underlying the phenotype in humans.

METHODS

The skin of the swollen foot and the non-swollen forearm was examined by (i) fluorescence microlymphangiography, to quantify functional initial lymphatic density in vivo; and (ii) podoplanin and LYVE-1 immunohistochemistry of biopsies, to quantify structural lymphatic density. Leg vein function was assessed by colour Doppler duplex ultrasound.

RESULTS

Milroy patients exhibited profound (86-91%) functional failure of the initial lymphatics in the foot; the forearm was unimpaired. Dermal lymphatics were present in biopsies but density was reduced by 51-61% (foot) and 26-33% (forearm). Saphenous venous reflux was present in 9/10 individuals with VEGFR3 mutations, including two carriers.

CONCLUSION

We propose that VEGFR3 mutations in humans cause lymphoedema through a failure of tissue protein and fluid absorption. This is due to a profound functional failure of initial lymphatics and is not explained by microlymphatic hypoplasia alone. The superficial venous valve reflux indicates the dual role of VEGFR-3 in lymphatic and venous development.

Prenatal diagnosis of isolated macrodactyly

Congenital enlargement of one or several digits of the hands or feet, known as macrodactyly, is a rare malformation. True macrodactyly, characterized by overgrowth of all mesenchymal elements, must be differentiated from that due to tumorous enlargement of a single element, as in hemangioma, lymphangioma or enchondroma. Furthermore, macrodactyly may be isolated, but it can also be associated with several syndromes. Here we present a case of prenatally diagnosed isolated true macrodactyly of the second toe of the left foot at 24 weeks of gestation, and discuss the key points in its differential diagnosis and management.

Hydrops fetalis: an unusual prenatal presentation of hereditary congenital lymphedema

OBJECTIVES

To report a rare case of primary congenital lymphedema (PCL) presenting as hydrops fetalis.

METHODS

The patient presented at 33(+4) weeks' gestation with polyhydramnios, massive bilateral hydrothorax, skin edema, scalp edema and minimal ascites. In utero thoracocentesis was performed and delivery was induced. Follow-up at 12 months of age revealed moderate bilateral foot edema with otherwise normal development.

RESULTS

The diagnosis of PCL was suspected on the basis of the family history. DNA analysis revealed a novel missense mutation, E1106K, in the tyrosine kinase domain of the vascular endothelial growth factor receptor 3 gene (VEGFR3/FLT4).

CONCLUSION

PCL should be considered in the differential diagnosis of hydrops fetalis. Knowledge of the favorable course, variable clinical presentation, therapy options and genetic basis should contribute to better pregnancy counseling and management.