Further delineation of the Yunis-Varon syndrome

Yunis-varon syndrome: further delineation of cardiovascular and endocrine outcome

Yunis-Varon syndrome is a rare autosomal recessive condition initially characterized by specific skeletal and ectodermal abnormalities, and a poor prognosis, due to neurological and cardiovascular involvement. We describe the cardiovascular and endocrine complications in a 26-year-old man who had been reported previously, adding dilated cardiomyopathy to the clinical features consistent with Yunis-Varon syndrome. Short stature, successfully treated with growth hormone, and hypertension secondary to bilateral renal artery stenosis expand the phenotype.

Yunis-Varón syndrome is caused by mutations in FIG4, encoding a phosphoinositide phosphatase

Yunis-Varón syndrome (YVS) is an autosomal-recessive disorder with cleidocranial dysplasia, digital anomalies, and severe neurological involvement. Enlarged vacuoles are found in neurons, muscle, and cartilage. By whole-exome sequencing, we identified frameshift and missense mutations of FIG4 in affected individuals from three unrelated families. FIG4 encodes a phosphoinositide phosphatase required for regulation of PI(3,5)P(2) levels, and thus endosomal trafficking and autophagy. In a functional assay, both missense substitutions failed to correct the vacuolar phenotype of Fig4-null mouse fibroblasts. Homozygous Fig4-null mice exhibit features of YVS, including neurodegeneration and enlarged vacuoles in neurons. We demonstrate that Fig4-null mice also have small skeletons with reduced trabecular bone volume and cortical thickness and that cultured osteoblasts accumulate large vacuoles. Our findings demonstrate that homozygosity or compound heterozygosity for null mutations of FIG4 is responsible for YVS, the most severe known human phenotype caused by defective phosphoinositide metabolism. In contrast, in Charcot-Marie-Tooth disease type 4J (also caused by FIG4 mutations), one of the FIG4 alleles is hypomorphic and disease is limited to the peripheral nervous system. This genotype-phenotype correlation demonstrates that absence of FIG4 activity leads to central nervous system dysfunction and extensive skeletal anomalies. Our results describe a role for PI(3,5)P(2) signaling in skeletal development and maintenance.

Primary pulmonary hypertension, congenital heart defect, central nervous system malformations, hypo- and aplastic toes: another case of Yunis-Varón syndrome or report of a new entity

Here we describe a patient with a new malformation syndrome which shows similarities with Yunis-Varon syndrome (YVS). Prenatal presentation included polyhydramnios, increased nuchal translucency, and bilateral hydrothoraces requiring pigtail insertion. Postnatal presentation revealed primary pulmonary hypertension (PPH), persistent hydrothoraces, one atrial and two ventricular septal defects, hypoplasia of the corpus callosum and cerebellar vermis, dilated interhemispheric ventricles, severe developmental delay with general muscular hypotonia, retinal anomalies, sparse scalp hair, sparse eyebrows and eyelashes, hypo- and aplastic nails, low-set dysplastic ears, loose nuchal skin, hypo- and aplastic distal phalanges of the toes as well as postnatal failure to thrive. High resolution molecular karyotyping in the patient did not reveal any causative chromosomal aberration. Since one patient with YVS and PPH has been previously reported, we assume a similar pathogenic pathway. However, molecular confirmation of the clinical diagnosis is not yet possible. It remains uncertain if the presented syndrome can be classified as YVS with PPH or if it constitutes a new YVS like entity.

New ocular findings in two sisters with Yunis-Varón syndrome and literature review

The Yunis-Varón syndrome (YVS) represents a rare autosomal recessive syndrome of easy recognition characterized by cleidocraneal dysplasia, absence of thumbs and halluces, distal aphalangia, ectodermal anomalies, and poor outcome. Here, we report two sisters with YVS who also had papillo-macular atrophic chorioretinopathy with "salt-and-pepper" appearance that could not be attributed to environmental or metabolic causes. Our best hypothesis is that the ocular findings in our two patients are part of the phenotypic manifestations of YVS. We suggest that an extensive ophthalmologic examination should be carried out in all children with YVS in order to define the frequency and nature of the ocular findings in these patients.

Yunis Varon syndrome

In this communication is reported a neonate with Yunis Varon syndrome, a rare autosomal recessive disorder, born to a consanguineously married couple who had microcephaly, wide cranial sutures, prominent eyes, hypertelorism, dysplastic ears, sparse hairs, cupid bow like upper lip with median pseudocleft and labio-gingival retraction. Bilateral hypoplasia of thumbs, absent great toes, short phalanges were other features. Additional features in this case included median pseudocleft unreported earlier and C.T. findings of underdeveloped gyri, ischemic changes in temperoparietal region and bilateral lacunar infarcts in middle cerebral artery territory.

A novel syndrome with dwarfism, poorly muscled build, absent clavicles, humeroradial fusion, slender bones, oligodactyly and micrognathia

We report on a 15-year-old girl with severe pre- and post-natal growth retardation, poorly muscled build, micrognathia, ulnar ray oligodactyly, absent clavicles, abnormal scapulae, humeroradial fusion, hip dislocation, small iliac wings, slender tubular bones and normal intelligence. An extensive search has failed to ascribe this association to a known condition. This child shared some clinical and radiological features with the Yunis-Varon syndrome but the normal intelligence and the ulnar ray oligodactyly of our patient does not support this diagnosis.

Yunis-Varon syndrome: evidence for a lysosomal storage disease

We present clinical and neuropathological findings in a female infant with Yunis-Varon syndrome (YVS) comprising absence of thumbs and halluces, aphalangia of fingers and toes, hypoplasia of clavicles, severely undermineralized skeleton (especially skull), microcephaly, and multiple nonskeletal anomalies. The patient also had a Dandy-Walker malformation, hydrocephalus, and hypertension, which were not reported previously in YVS. The infant excreted an abnormal unidentified oligosaccharide. The patient died at day 108 with severe neurological impairment. Autopsy showed prominent intraneuronal inclusions with vacuolar degeneration, mainly in the thalamic, dentate nuclei, cerebellar cortex, and inferior olivary nuclei. No storage phenomena were observed in other tissues. These findings strongly suggest that a lysosomal storage disorder is involved in the pathogenesis of Yunis-Varon syndrome.

Clavicular hypoplasia, zygomatic arch hypoplasia, and micrognathia: a newly defined syndrome

We report on a 6-year-old boy with a previously undefined syndrome of clavicular hypoplasia, frontonasal malformation, zygomatic arch hypoplasia, micrognathia, and normal intelligence. His condition differs from similar syndromes on the basis of unique facial findings such as microcornea, stellate irises, and a midline maxillary cleft. We present his case, a review of the literature, and propose the acronym CHZAM, for clavicular hypoplasia, zygomatic arch, and micrognathia, to represent this syndrome.

Atrophy of the left lobe of the liver and anomalous hepatic vessel in a patient with Yunis-Varon syndrome

Yunis-Varon syndrome is inherited as an autosomal recessive trait. It is characterized by facial and digit anomalies. This report describes a young woman with clinical features of this syndrome, atrophy of the left lobe of the liver, and a vascular anomaly. Liver abnormalities have not been described as features of this rare syndrome.

Generalized lysosomal storage in Yunis Varón syndrome

Muscle biopsy in a neonate with features of Yunis Varón syndrome revealed a vacuolar myopathy with evidence of lysosomal storage disease. Similar vacuoles were also present in heart, cartilage, central nervous system and cultured fibroblasts. Although the histologic findings in the central nervous system resembled those of infantile acid maltase deficiency, the essayed lysosomal enzymes were normal. Chromatography of urine revealed abnormal bands of unidentified oligosaccharides. This is the first report of generalized storage disease in Yunis Varón syndrome. The biochemical defect is unknown.

Congenital heart malformation in Yunis-Varón syndrome

We describe a male infant with Yunis-Varón syndrome who has tetralogy of Fallot. This appears to be the first case of Yunis-Varón syndrome associated with congenital heart malformation.

Digito-reno-cerebral syndrome: confirmation of Eronen syndrome

In 1985, Eronen et al. described a new autosomal recessive syndrome with absence of the distal phalanges of the toes and fingers, renal defect and cerebral anomalies (dilated ventricles or seizures). Two unrelated children affected by this syndrome enable us to accept its autonomy and delineate its nosology. Variability of the expression of the renal and cerebral manifestations is emphasized.

Hypodontia, impacted permanent teeth, spinal defects, and cardiomegaly in a previously diagnosed case of the Yunis-Varon syndrome

The Yunis-Varon syndrome is a rare hereditary disorder with ectodermal and skeletal anomalies that include agenesis or hypoplasia of the clavicles, craniofacial disproportion with severe micrognathia, digital anomalies, prenatal and postnatal growth deficiency, and neonatal death. Only 12 cases have been reported in the literature. Although neonatal death is a significant feature of this syndrome, two case reports describe children, both males, who were 30 months and 3 years of age at the time of investigation. The 30-month-old child was reexamined at 11 years of age, and had further clinical and radiologic features that included hypodontia, impacted permanent teeth, spinal defects, cardiomegaly, bilateral hearing loss, and metatarsus adductus. Children who survive the neonatal period and continue to thrive with many of the features of the Yunis-Varon syndrome as well as the new features described in this article may not have a distinct yet related syndrome.

Yunis-Varon syndrome with severe osteodysplasty

We report two male sibs and two female sibs from separate families, both with normal parents, who had a lethal condition with features of the Yunis-Varon syndrome and radiological signs of severe osteodysplasty. Autosomal recessive inheritance is likely in both families. The additional features described represent further delineation of the phenotype of the Yunis-Varon syndrome.