Consecutive Sisters Born with Opposite-Sided Congenital Below-Elbow Amputations

ROBERT WARNER, M D.


The most common juvenile amputation1, 2 is an absence of the distal forearm and hand, usually referred to as below-elbow amputation or terminal transverse partial hemimelia. It has long been well established that this defect is (a) more common in girls and (b) more frequent on the left side 1 .

The concurrence of left over right and female over male has been difficult to attribute to a genetic basis. Histories of its occurrence in families, and especially in siblings, have indeed been rare.

There is some confusion in the literature over the term amputation. One must distinguish between in-utero separation of a part of an already formed limb and a failure of such formation. Warkany 3 has referred to the amputated extremity section being found in the uterus along with the rest of the child, and he points out a tendency to hereditary occurrence. In contrast, he states, "The absent parts of the appendicular skeleton may never have been formed (aplasia or agenesis) and nonexistent limbs cannot be amputated." He further states that the stump rarely represents exactly half of the forearm (or leg), so that both terms hemimelia and amputation are scientifically incorrect and should he replaced by reduction, agenesis, or peromelia.

However, the accepted and commonly used terms remain amputation and hemimelia as defined by Frantz and O'Rahilly, both in their proposed "International Classification of Congenital Limb Deficiencies" 1 and in other publications 2,4 . In their clinic, 112 of 300 cases were transverse terminal hemimelias. In our Buffalo clinic at the Children's Rehabilitation Center, 190 of 332 cases were congenital. Of these, 81 have a single below-elbow defect, of which there are 50 girls to 31 boys, and of which 53 are left and 28 are right sided.

Similarly, Birch-Jensen 2 in Denmark found this anomaly to have a frequency of one in 25,000 and states they are nearly always unilateral and usually occur sporadically, but he reports one instance of the occurrence in sibs and several in cousins. Yet, in spite of this, Frantz and O'Rahilly categorically state, "Genetics: Non-Hereditary" for this condition.

As Warkany stresses, and as all of us in teratology and dealing with children with amputations are well aware, there is a strong hereditary aspect to congenital amputations if (a) they are multiple (several limbs involved), (b) they are accompanied by other anomalies, or (c) there are other systems involved. These conditions may be integral parts of chromosomal abnormalities or other genetically induced recessive, dominant, or sex-linked syndromes. But it has been a fairly universal practice for those who give genetics counselling to families after the birth of a child with a single, below-elbow amputation to give them reassurance that this is probably nonhereditary and has only a very minimal (almost nonexistent) chance of recurrence.

Case Report 1

D.J. was born November 7, 1974, and was seen at 2 and 1/2 months of age. She is the result of her native American Indian mother's sixth pregnancy. The mother had five previous pregnancies by her first husband, of which the first, second, and fourth pregnancies were miscarriages at six to seven weeks. The third and fifth resulted in living sons (July 1966 and May 1968) who are essentially normal, healthy, and athletic. The mother has been troubled with ulcers controlled by diet, and with sinus problems. This is the first child for the father, also a native American Indian. He is subject to frequent severe colds, allergy, and intermittent high blood pressure. Both were 27 years of age and knew of no consanguinity.

The family disease history is replete with considerable amounts of diabetes, hypertension, cancer, and rheumatic fever, and a maternal grandmother who was out of the family for some time with tuberculosis but is completely recovered. The pregnancy history had many untoward events, including an auto accident with whiplash and dislocated hip, continual sinusitis, and morning sickness which was eventually called flu and treated with antibiotics. There were many medications: Maalox, Valium, antibiotics, and others. There was very little weight gain, only 7.3 kg (16 lbs.) total. The child was born at Buffalo General Hospital, full term less only two days and weighing 3.76 kg (8 lbs. 4 and 1/2 oz.). It was a vertex delivery with forceps, with spinal anesthesia and induced with intravenous pitocin two days after manual rupture of the membranes. The baby had spontaneous respirations and was placed under bili lights for borderline jaundice. The defect of the arm was noted at once, and her physician referred her to the Children's Rehabilitation Center. There were no illnesses except diarrhea, which lasted four weeks. At six weeks the patient was treated in the Children's Hospital for diarrhea. Immunizations had not yet started. Feeding history is tied up with the history of diarrhea. She was changed from Enfamil with iron to Enfamil without iron, then to Similac, and there was early institution of foods by the mother. She was now eating normally. Behaviorwise, the mother used a pacifier to prevent thumb and stump sucking. The patient passed her milestones early with good head control and early smiling. She temporarily exhibited head rolling, which she has since discontinued.

On physical examination, she was a normal little girl with measurements of greater than 3 months, at 2 and 1/2 months ( Figure 1 ). She was a stocky, relatively long-legged, healthy newborn with no abnormal findings other than the right below-elbow congenital amputation. The left upper and both lower limbs are well formed with nice fingers and toes and normal palmar markings. The deep tendon reflexes are difficult to elicit but are physiologically and bilaterally equal in the legs. The plantars are somewhat equivocal but generally down. The left upper limb is nicely formed, although there is quite a deep dimple both laterally and medially at the elbow. The right upper limb ends in a nicely rounded umbilicated stump which has a deep crescentic overfold and a little protrusion with tiny nubbins that probably represent fingers. This stump is 5.5 cm below the bent elbow and 5 cm below the elbow fold (the lower of the two elbow folds which she presents). The stump is of good color and good warmth. She has good deep tendon reflexes at the elbow and triceps and excellent flexion and extension of the stump with some rotation. The ulna seems to have a normal articulation with the humerus and is approximately 5 cm in length ( Figure 1 , Figure 2 , and Figure 3 ).

Our recommendations were to proceed through Amputee Clinic and fit her with a conventional right below-elbow prosthesis. We prophesied she would be a good limb wearer with understanding parents.

The physiatrist concurred with the diagnosis, noting a moderately short stump. Examinations by occupational therapist and psychologist preceded her amputee-clinic visit at 5 months of age, at which the orthopedist in conjunction with other team members ordered a

"Right below-elbow prosthesis: double-wall socket of laminated plastic; a flexible elbow hinge; a figure-of-eight harness with a Northwestern ring and 1/2-in. dacron material with an axilla loop; a single control system with a P-12 terminal device; a WE-100N disconnect unit." She was then seen with her newly received prosthesis on May 22:"There is a problem from the strap at the shoulder. This will be pinned to the T-shirt. There is some irritation in the left axilla. This will be solved by wearing different types of T-shirts. There are no other problems at the present time. It was felt that 20 visits of training will be necessary. This was authorized," She was regularly followed in the clinic in June, August, and November 1975, and in January 1976 was found to have outgrown her first prosthesis: "A new prosthesis, double-wall below-elbow socket with PC-SO elbow hinge and a half cuff with a single control system, using the same terminal device, WF-300N disconnect unit, with two detachable figure-8 harnesses with Northwestern ring and Hosmer axilla loop was ordered. Twenty more visits for training were authorized. D. is progressing well and wearing her prosthesis most of the time."

She was checked in clinic when she received this prosthesis in February 1976, and was followed in May, July, and October of that year and January, April, and July 1977, with no serious or specific problems. She was using her prosthesis well.

In the interval in late December 1975, the parents sought counselling to discuss the possibility of their having a second child and the chances of possible recurrence of D.J.'s problem in another sibling. I quote from that counselling session:"The first pregnancy appeared to have been a disaster in many ways with illness and medications but with no evidence that any of these affected the type amputation with which D.J. was born. The fact that this is the most common of all anomalies, had the predilection for one side and one sex, for no obvious or understandable reason under our present knowledge, means that it is caused by totally unknown factors. Regardless of the many factors that could have been adverse in her pregnancy, we are still left with a congenital anomaly of unknown etiology. "There is no evidence of this being an inherited anomaly as it is not associated with chromosome anomaly. There are essentially no reported cases of two in one family of siblings, although they are reported in families of more distant relationships, and no evidence of increased consanguinity. No one could give them any guarantee that another child like D. J. would not be born, but they were assured that the chance of recurrence in the same family was very minimal. The aminoaciduria was also discussed. Since there was no knowledge as to the etiology of either of these conditions, no true figures of incidence were available."

Because we were following D.J. regularly in clinic, we knew of the mother's pregnancy. Yet it came as a great shock to all of us when the mother called and asked if she could bring in her new baby with a left below-elbow amputation.

Case Report 2

J.J. was born July 1, 1977, and was examined on July 7, 1977. Both parents were now 29 years of age. This was their second child. The mother's previous pregnancy is outlined in the first case. The father in the interim had surgery on his back twice: first, a tumor of spinal cord February 1976, then a ruptured disc March 1976. He was now allergic to aspirin.

J.J. was the result of an uneventful pregnancy, full term plus three days with a five-hour labor of "tough" four-minute pains, a vertex presentation, spontaneous delivery with episiotomy, weighing 3.97 kg (8 lbs. 12 oz.) and considered a normal neonate except for the congenital left amputation of forearm and hand. She sucked well on the breast every two to six hours. She tried to suck her normal (right) fingers and could raise her head from prone at six days. She was of average proportions for her weight and age, with a head size greater than expected but with normal Indian facies ( Figure 4 ). The physical examination was normal except for the left upper limb, which ends in an umbilicated stump at the end of the humerus. The left forearm is only about 1.2 cm long and the left humerus is 9.5 cm (compared to 10.5 cm on the right), and it has very little bone and just a small nubbin representing rudimentary hand and fingers. Essentially, there is very little below the elbow. With a 1-cm difference in the upper part of her arm, the 14.5-cm length of lower arm on the right approximates the total shortage ( Figure 4 , Figure 5 , and Figure 6 ).

Family history was the same as before with the exception that following the birth of the second affected child it was noted that a paternal uncle's child was deaf, and several more family members were noted to have allergies. Also, it was determined that both the mother and father appeared to be distant cousins of an Indian lady who is the mother of M.L., another left below-elbow amputee previously treated in our clinic from the same reservation.

Exhaustive research and digging into the family background failed to reveal any consanguinity, with only the presence of remote common ancestors on either the maternal or paternal side of the family of the mother of M.L. (This mother was the grandchild of an uncle-niece consanguinous marriage.) Because there were matriarchal clans with taboos on marriage within the clan, it was determined further that it is unlikely that there exists much consanguinity on the reservation. Although both of these parents of our two cases are members of the "Heron" clan, they are "Herons" from different Indian Nations (Seneca and Cayuga), making the possibility of consanguinity extremely remote.

Conclusion

In spite of the presently unresolved problem of the existence of possible consanguinity and occurrence of other single below-elbow amputations in a distant cousin (which will be dealt with in later publications if the intricacies of their family tree can be resolved), this family with two well-documented consecutive below-elbow single amputations must serve as a warning to shake our complacency in accepting the nonhereditary nature of this common defect.

There is, of course, no proof that this phenomenon is hereditary. It could well be a teratogen operating in the mother or her environment. In this case, the occurrence in native American Indians living on a reservation, with much opportunity for intermarriage and confused relationships which suggest consanguinity, the question of hereditary influence becomes increasingly potent and invites one to draw such a conclusion.

References:
1. Proposed international terminology for the classification of congenital limb deficiencies. Dev Med Child Neurol, 17, Suppl 34, 1975.
2. Frantz, C. H., and R. O'Rahilly, Congenital skeletal limb deficiencies. J Bone Joint Surg,43A:8:1202-1224, December 1961.
3. Warkany, Josef, Congenital Malformations. Year Book Medical Publishers, Chicago, 1971, pp. 944-954.
4. O'Rahilly, R., Morphological patterns in limb deficiencies and duplications. Am J Anat, 89:135, 1951.
5. Birch-Jenson, A., Congenital Deformities of the Upper Extremities. Ejnar Munksgaard,
Copenhagen, 1949.