*Dept. of Obstetrics and Gynecology, University of New Mexico School of Medicine, 2211 Lomas  Blvd., NE, Albuquerque, NM 87131-5286. Ph: 505-272-6611. Fax 505-272-6385

Synonyms: None.

Definition: Pterygiums are webs of skin across joints; lethal multiple pterygium syndrome demonstrates camptodactyly, facial anomalies, hypoplastic lungs and heart, cystic hygroma and skeletal anomalies^1-8.

Etymology: pterugion: like a wing, from pterux: wing.

Prevalence: Rare: less than 200 cases reported.

Etiology: Autosomal recessive^1-4 or X-linked inheritance^9,10 syndrome. It is associated with the Fetal Akinesia sequence.

Pathogenesis: Mostly speculative; fetal edema may play a role in producing fetal abnormalities². Edema probably causes extracellular pressure on fetal tissue, resulting in bony fusion, muscle hypoplasia, pulmonary hypoplasia, etc².

Associated anomalies: Multiple pterygia, camptodactyly, arthrogryposis, cystic hygroma, nonimmune hydrops, hypoplastic lungs, hypoplastic heart, skeletal abnormalities⁴.

Differential diagnosis: Pena-Shokeir syndrome, jugular obstructive lymphatic sequence, non-immune hydrops.

Prognosis: Lethal.

Recurrence risk: 25% in the autosomal recessive form.

Management: Pregnancy termination should be considered once the diagnosis is established.

MESH BDE 2274 MIM 253290, 265000 312150 POS 4255 ICD9 228.1 CDC 228.100

Case report

A 19-year-old G₁ P₀ at 19 weeks of gestation was referred to the University of New Mexico Obstetrical Ultrasound Unit for evaluation because the fetus was found to have a cystic hygroma on routine ultrasound examination by her primary care provider.

Our ultrasound examination revealed a cystic hygroma and hydrops consistent with jugular obstructive lymphatic sequence (fig. 1). On the overall evaluation we saw a fetus which never moved in a period over 1 hour; the mouth remained open throughout the study. The upper extremities showed severe flexion and fixation at both elbows and wrists (fig 2). The lower extremities were also fixed and flexed, showing signs of edema and talipes equinovarus (fig. 3). The patient was evaluated by a team consisting of a perinatologist, pediatric dysmorphologist, and genetic associate. Pregnancy termination was offered to the patient, which she refused. An amniocentesis was performed which revealed 46XX. Two weeks later on a regular OB visit, the fetus was found to have no heart tones. Prostaglandin induction of labor was performed.

Figure 1: Posterior septated nuchal mass consistent with cystic hygroma.

Figure 2: Upper extremities showing severe flexion at the level of the wrists.

Figure 3: The lower extremities with evidence of edema and talipes.

Postnatal assessment

The fetus showed the following external features: growth restriction, multiple pterygia including chin to sternum, axillary, antecubital, crural and popliteal. Large cystic hygroma with retroflexed neck. Open mouth and eyes. There was evidence of retrognathia (fig 4). The couple refused an autopsy but was counseled about a 25% chance of recurrence based on dysmorphic findings in the fetus.

Figure 4: Photograph of the fetus showing evidence of contracted joints and cystic hygroma

Discussion

Definition

Pterygium is used to describe webbing of the skin across the joint. The term means "wing-like". Limb pterygia at birth indicates an abnormal developmental process probably occurring in the first trimester and involving reduced mobility of the webbed limb. The severity of the web apears to correlate directly with the degree of hypomobility of the affected joint and with the time in development at which the movement reduction began³. This syndrome consists of a constellation of multiple anomalies associated with fetal akinesia sequence and fixation and hypomobility of the joints.

Prevalence

Unknown. The incidence may be higher in consanguineous marriages.

Etiology

This is an autosomal recessive syndrome most commonly due to fetal akinesia sequence. In general, there are four major reasons for decreased movement in utero:

·        a myopathic process

·        a neuropathic process

·        a connective tissue disorder

·        a limitation of space, such as oligohydraminios.

Any of the above processes can be associated with a variety of clinical situations and lead to decreased fetal movement and secondary contractures¹.

Classification

Hall et al. have proposed a classification of the lethal pterygium syndromes:

·        without bony fusions but with limbs tightly flexed

·        with fusion of the vertebral bodies

·        with other bony fusions^2,7.

Pathogenesis

Although the pathogenesis is unclear, the in utero onset of fetal edema in these cases, together with decreased movement and abnormal body proportion, can allow prenatal recognition. The role of in utero embryonic and fetal edema might play a role in producing anomalies present at birth. Edema may cause extracellular pressure on fetal tissue, probably resulting in bony fusion, muscle hypoplasia, pulmonary and gut hypoplasia, genitourinary anomalies, etc².

Associated anomalies

Multiple pterygium syndrome presents with a distinct group of anomalies (see Table 1).

Table 1: Associated Anomalies

Differential diagnosis

The differential diagnosis should include syndromes of the fetal akinesia sequence, such as Pena-Shokeir syndrome, trisomy 13, trisomy 18, and fetal alcohol syndrome¹. Turner syndrome and cases of jugular obstructive lymphatic sequence should also be considered. Some authors have also included cases of non-immune hydrops as a differential diagnosis.

In table 2 we present the ultrasonic findings and outcome of four prenatally diagnosed cases.

Table 2: Ultrasound findings of prenatally diagnosed cases with lethal multiple pterygium syndrome.

Prognosis

Poor, uniformly lethal.

Recurrence risk

As in autosomal recessive syndrome, the recurrence for each pregnancy thereafter is 25%.

Management

After the diagnosis is confirmed, pregnancy termination should be offered. Cesarean section should be avoided in cases in which expectant management is decided.

References

1. Stevenson RE, Hall JG, Goodman RM. Human malformations and related anomalies (Vol II). Oxford University Press. New York, 798-804, 1993.

2. Hall JG. Editorial Comment: The lethal multiple pterygium syndromes. Am J Med Gen 17:803-07, 1984.

3. Hall JG, Reed SD, Rosenbaum KN, et al. Limb pterygium syndromes: A review and report of eleven patients. Am J Med Genet 12: 377-409, 1982.

4. Chen H, Immken L, Lachman R, Yang S, et al. Syndrome of multiple pterygia, camptodactyly, facial anomalies, hypoplastic lungs and heart, cystic hygroma, and skeletal anomalies: Delineation of a new entity and review of lethal forms of multiple pterygium syndrome. Am J Med Genet 17:809-26, 1984.

5. Zeitune M, Fejgin M, Abramowicz J, et al. Prenatal diagnosis of the pterygium syndrome. Prenat Diagn 8:145-49, 1988.

6. Lockwood C, Irons M, Troiani J, et al.: The prenatal sonographic diagnosis of lethal multiple pterygium syndrome: a heritable cause of recurrent abortion. Am J Obstet Gynecol 159:474-6, 1988.

7. Anthony J, Mascarenhas L, O"Brien J, et al.: Lethal multiple pterygium syndrome. The importance of fetal posture in midtrimester diagnosis by ultrasound: discussion and case report. Ultrasound Obstet Gynecol 2:12-16, 1993.

8. Kirkinen P, Herva R. Leisti J. Early prenatal diagnosis of a lethal syndrome of multiple congenital contractures. Prenat Diagn 7:189-96, 1987.

9. Carnevale A, Hernandez AL, De los Cobos L: Sindrome de pterygium familiar con probable transmission dominante ligada al cromosoma X. Rev Invest Clin 25: 237-44, 1973.

10. Tolmie JL, Patrick A, Yates JR: A lethal multiple pterygium syndrome with apparent X‑linked recessive inheritance. Am J Med Genet 27:913-919, 1987.