Zimmermann-Laband syndrome in an infant with an atypical histologic finding

Zimmermann-Laband syndrome and infantile systemic hyalinosis: an enigma with two separate terms with overlapping features: a case report

BACKGROUND

Zimmermann-Laband Syndrome (ZLS) and infantile systemic hyalinosis (ISH) are rare genetic disorders. They are characterized by various spectrum manifestations. In spite of other case reports, this case with features of both syndromes was reported by oral medicine specialists and oral and maxillofacial surgeons.

CASE PRESENTATION

In this study, we reported an 18-months old female patient with gingival overgrowth. This phenomenon completely embedded all the erupted teeth. In this case, the presence of multiple papulonodular cutaneous lesions is a newly observed aspect that has rarely been reported in the existing literature. Gingival overgrowth was excised under general anesthesia. At six months of follow-up after surgery, mastication and breathing problems were improved. Aesthetic aspects were ameliorated in terms of gingival appearance.

CONCLUSIONS

To date, due to the ambiguous presentations, both syndromes remain an enigma for specialists. A timely diagnosis could be crucial for prognosis and preventing severe further surcharge. Dentists could play an important role in the diagnosis of rare disorders.

Clinical and genetic study of two patients with Zimmermann-Laband syndrome and literature review

Zimmermann-Laband syndrome (ZLS) is a rare MCA/MR condition mainly characterized by gingival hypertrophy, hypo/aplastic nails and distal phalanges, hypertrichosis and intellectual disability. The molecular basis of ZLS is unknown. Most patients are sporadic, although familial aggregation is also observed with different inheritance patterns. We report on two unrelated children with full-blown characteristics of ZLS. Remarkable variability in expression included severity of neurocognitive involvement and extent of appendicular and facial features. In both, comparative genome hybridization array at a ~ 75 Mb resolution resulted negative, while aminoacid metabolic screening revealed high plasma levels of hypoxanthine and xanthine in one. Literature review identified 50 previously published patients (27 females, 23 males), including 14 familial, clustered in four pedigrees, and 37 sporadic. Tabulation of clinical features confirmed the core phenotype and identified developmental delay as the unique major clinical problem (occurring in 40% of the cases) with a moderately high risk of epilepsy (13%). Segregation analysis in the 20 sporadic patients with available data on healthy sibs and a single pedigree with affected sibs was significantly in contrast with an autosomal recessive mutation. An autosomal dominant mutation with high mutation rate and rare instances of germinal mosaicism seems the most likely inheritance pattern. This work may represent a starting point for future molecular studies aimed at identifying the molecular basis of ZLS.

Candidate loci for Zimmermann-Laband syndrome at 3p14.3

A male with 46,XY,t(3;17)(p14.3;q24.3) presented with gingival hyperplasia, hypertrichosis, unusually large ears and marked hypertrophy of the nose, characteristic of the Zimmermann-Laband syndrome (ZLS). Other features include large facial bones and mandibles, large protruding upper lip, enlarged fingers and toes, strabismus, and enlarged phallus. Knowledge of a 46,XX,t(3;8)(p21.2;q24.3) reported previously in a mother and daughter with ZLS suggests that the 3p14.3-p21.2 region may contain a gene responsible for ZLS. We have reassessed the chromosome 3 breakpoint region of the t(3;8) and revised its breakpoint location to 3p14.3, based upon an updated human genome sequence assembly. Using fluorescence in situ hybridization (FISH) with BAC clones, we have also identified a breakpoint spanning clone at 3p14.3 in our t(3;17) patient, thereby narrowing the breakpoint to a region of approximately 200 kb. These data suggest that the gene responsible for ZLS is located in 3p14.3 and implicates four likely candidate genes in this region: CACNA2D3, encoding a voltage-dependent calcium channel, LRTM1, a gene of unknown function embedded within CACNA2D3, WNT5A, encoding a secreted signaling protein of the WNT family, and ERC2, which codes for a synapse protein.